SoulseekQt kills my internet connection

For the last few builds, I have had major problems using Soulseek. It has been the first time in 12 years that I've had any such issues. I am on a Windows 7 PC.

The problem:

When I open SoulseekQt, things function for a very short period of time. Sometimes, for only a few seconds; other times, for up to a minute. But then my internet connection dies and sometimes briefly comes back, on and off, until I close Soulseek. As soon as I do that, the internet again functions properly. While Soulseek is running, the internet will function normally only for a few moments at a time before again going out. Not only Soulseek's connection is affected by this problem--the internet connection dies across the entire computer. Other machines on the network, however, are NOT affected. This problem happens during both wireless and wired connections, but the wired connection is much more likely to slow to a crawl than to completely disappear. I'm most often connected wirelessly.

For some reason, the Soulseek client itself functions very, very slowly during a wired connection. Lots of (Not Responding), hang, and all-around slowness. It takes several minutes just to get the program to respond so that I can quit it. The last time I checked in the Task Manager, the memory use was a staggering 1,350,000 K, though I have no current downloads or uploads. This happens regardless of whether or not I am downloading, uploading, or searching for something.

My ports are properly configured and, when the internet works, Soulseek's check verifies this. Firewall exceptions are in place. No anti-virus conflicts. No other programs, file-sharing or otherwise, have these issues when Soulseek is not running.

Can you suggest anything? I really want to keep using Soulseek. It's like family, after all these years! But I don't know what to do. I have no other ideas and could find no solutions that worked for me. Thank you so much for any help or suggestions you can offer, and thanks for reading this long post. It really means a lot.

Hi eccles
as your other PCs has no problem with the connect, your router is out of question here. The memory consumption seems very high, for no visual reason.
SLSK creates a lot of traffic in the first seconds, but even older computer could cope with that. Have you shares huge amount of files (>100.000)? Have you switched back to a version where it worked flawlessly? Have you tried using it in another (windows user) profile? Export +import helps here to set it up again fast.
My first thought (as SLSKqt runs very smoothly under Windows) would be that your network interface collapse or interferes here (OS Firewall . Have you tried different Port settings just for testing? Is the port checker working?
When you upgraded from a version before 2015 maybe the config files got invalid/messy. With another user (=no config exits) it's easy to test.

I'm currently sharing very few files. I wanted to be sure to have small libraries and to keep my download/upload speeds limited. That way, I could be sure that those weren't the issues.

I switched ports, but it did not fix the problem. When the internet is working, the port checker works and says that everything is properly configured (regardless of which ports I use--all of them have checked out OK); of course, the internet is often NOT working when Soulseek is running.

I also completely disabled Windows Firewall, but that did not solve the problem.

I have not tried to use an older version of Soulseek because I am not sure where to find the older builds. If I do try that, do I first need to do anything other than uninstalling the latest build?

Thank you for your help! I hope we can figure out a solution. I've never done "export+import," before, so I'm not 100% sure what I need to do. Do you have any advice?

Hi eccles
nothing needs to be done when Up/downgrading. SLSKqt is very integre so only one executable and that's it; easy to patch/change.
A different windows user profile is something I'd try first.
What puzzles me a bit is the (Web) Port Check: only those ports you allowed in your firewall/Router should work (else you use a DMZ forwarding). The RAM amount without huge libraries is another indication sth. is wrong with the startup.
I'd do:
a) create a new profile and use it to test if slsk AND internet is working fine! SLSK is not interfering into the TCP/IP stack
b) log in with your old user and follow these instructions:


I tried a different Windows user profile, but the problems did not change. Because the problem was the same, I did not bother importing my settings.

I do not have DMZ forwarding enabled. As for the ports, SoulseekQt has always worked for me regardless of whether or not I manually forward the ports. But I DO forward them because my understanding is that this is the "correct" way to set up the client. I'm also not sure why the integrated port checker gives me an OK even when I have not yet forwarded the ports. Seems strange.

Something I noticed is that the Soulseek port checker does not show my computer's IPv4 static IP address ( Instead, it shows my WAN IP address ( Could this be part of the issue? I don't think that this is a problem, since the WAN IP address is what directs traffic to/from my computer, but I am not an expert. I might be wrong.

If that is the problem, I'm not sure what to do. If it isn't, I'm still not sure. Ha. Again, thank you for your help and advice. I'm sure that there must be a solution, but I'm getting nervous.

Oh, and the high RAM usage only seems to happen with a wired connection. When I'm trying to use Soulseek wirelessly, only the internet connection is affected.

Hi eccles
as it happens with the other profile as well it's no config setting, so the import is not necessary. With Port Forwarding your client can hear and reply on the IPv4, so that's why it's necessary. With a DMZ every traffic is forwarded to the DMZ IP, but when the port checker say OK, your local IP Stack can operate on that two IP addresses. As PF works in the same way as to expose your client machine (on this forwarded ports only) to the internet it works only with the Inet IP.
There's no explanation I have for this behavior (apart from a DMZ "attack like" flooding).
Case: when you change the ports to e.g. 10015 (+the hidden following port 10016) in SLSKqt, then close it and start again, do the web Port checker it still says Port OK (of course WITHOUT changing a thing in your router)?

RAM usage should be the same WLAN/LAN it's just a different network connector ..... lots of mysteries

Okay, I just switched to 10015/10016 and made no changes in my router configuration. Interestingly, the Port Checker still says that both ports are open and configured properly (when the internet is briefly working). And when the internet connection is able to remain active, Soulseek IS working. The problem remains that the internet quickly dies. It comes back for a few seconds at a time, every few minutes, but only works normally when I close Soulseek.

I agree that some of the symptoms seem to suggest "attack like" flooding, but I can't figure out why that would suddenly be an issue after never being a problem for so many years. I saw in some older threads that people sometimes have to increase the half-open TCP connections limit, but everything that I have read said that this is not an issue with Windows 7 (since it does not impose a limit). So I really don't know what else to think.

Look into your SLSK config menu. Is the Upnp Feature deactivated? Else it would (when upnp works, which is rare) open the right ports automatically.
What you describe is the symptom typical for DMZ beeing attacked (which normally bounces from any good firewall/router.
More modern router are able to detect P2P Systems and a) block it or b) open their gates (so no config is needed) to it. As the SLSK protocol is very easy to detect (some ISPs even block it for fun being law abiding ...) it might be into some modern router.
Have you changed your ISP or Router as well?
Just to decide if it's an OS problem: do you have a second (same OS preferred) machine to test SLSK on it for comparison?

UPnP IS activated. NAT-PMP is NOT.

My ISP has not changed, and I know that it does not block Soulseek (at least in this area, as many of my friends still use it with no problem on both PC and Mac). I DO have a new router, but my Soulseek problems started before I got it and it has not had any negative impact on other P2P programs. In fact, everything else actually works better with this router than my old one.

Unfortunately, I do not have a second PC with Windows 7. I have a much older computer with XP. I will test it and report. QT worked fine on it the last time that I tried, but that was at least a year ago.

Thank you so much!

Also, I have been trying to leave QT running in the background for longer periods of time. The problems seem less serious when I am not searching for or downloading anything; but the problems still do happen. Nobody has tried to grab anything from me for quite a while, which I do think is strange. I don't know whether or not this information is useful, but I figured it couldn't hurt to share it. Again, thanks.

Update: Soulseek Qt build 2015.2.21 works perfectly on my ten-year-old Windows XP machine even without me manually forwarding my ports. No problems. UPnP is on, NAT-PMP is off. I haven't updated the build because I'm nervous about it causing the same problems that have happened on my day-to-day computer.

with uPnP enabled the ports are following you automatically, which explains the behavior=> OK. SLSKqt works even on Windows 2000 machines, so don't worry. It's all about finding the flaw. So it's not a SLSK problem with your network which is good to know. As long as SLSK under XP works perfectly it's something on the win7 system or installation which causes it.
I'd advise to disable upnp on the Win7 machine and forward the ports manually and put the right values into SLSK and after a restart of SLSK test if it's still a problem.

I turned off UPnP on the Windows 7 client and went ahead and forwarded the ports on my own. The internet connection is still on-and-off, when QT is running...BUT the problem is not as bad. The internet would usually stay okay for several minutes and then briefly cut out. It would then come back, stay okay for several more minutes, and then cut back out. This seemed to happen both when the client was idle and when I was trying to search for or download something. I still don't seem to be returning any results for searches. And the client still hasn't uploaded anything to any other users. Thanks for your continued help! I'm glad that the problem is at least improving.

that's not a real progress. SLSK is normally not changing anything in your OS (just as your XP machine proves). I'd go the way to see what brakes away in your INet connection. A (continues) ping to your gateway (=router) is the next step. If that works (even when the Inet connect seems to drop) ping some stable website in the internet, like and see if the ping stays as well.
Could U describe the "Connection is lost" a bit more? Does websites not react anymore, your desktop/app or does the connection tray icon goes offline/online.

Hi, Sammy. I have no explanation for this, but SoulseekQt has been working well since I starting running it while trying to ping the router. For the first time in almost a year, everything is fine. I haven't changed anything at all since my last post. I don't understand it, but I am not complaining. If the problems return, then I'll make another post. Thank you so much for your help and patience! I really appreciate it. I hope that I don't need any more help, but I'm happy to know that if something does go wrong that people here are so generous and helpful. Thanks!

Hi eccles
you're welcome & Happy Sharing!


My problems have returned! They are the same as before.

When I use Soulseek, I am not able to ping my router or any websites. I get "Request timed out" or sometimes "Destination host unreachable."

To answer your previous question--when the internet goes out, websites do not load. My computer and desktop function normally. Soulseek does not freeze, and I can still click on tabs and get around in it; but there is no internet connection. The internet connection icon in the tray says that there are connection problems/there is no internet connection.

I am very confused. I have not changed ANYTHING since we last spoke. I was using it for the last week without any trouble. I could download and upload just like in the old days. But now the problems are back. Thanks for your help. I hope we can figure it out.

Hi eccles
as before: it's surely not SLSKqt which interferes with your computer. As the ping to your gateway drops as well I'd only only guess:
a) LAN card driver (gets flooded by the amount SLSK interchanges)..... this is very very rare but the most likely. WLAN is very sensitiv to such
b) some kind of firewall which gets flooded and collapses
c) some Windows Interface (NDIS) drops being flooded (flooded means here it receives more input than it could cope with at that situation)

Typically that behavior (Inet drops) should be not only with SLSK, but with all massive data exchanging procedures like torrent, web streaming, web games ,....

What I'd do:
a) clone your disk (so you could easily step back when there's no salvation with it)
b) update the LAN/WLAN/whatever driver you use for the local LAN=> look at the date of the old/new driver.
c) use a different LAN/WLAN card (different manufacturer! so different drivers); Realtek is in any way a bad one, so is most Atheros cards, some Broadcom WLANs are just as crappy as the cheapest cards available; the broadcom LAN cards are OK, so are Marvell or Intel
d) run a Win7 repair (which is a normal install, but it tooks all the config settings from the current installation

if the above (test after b/c/d if the error is still there

Afaik you have tested the different windows user already, didn't you?

I have no problems with torrenting, web streaming, online gaming, or any other such activities. It is only SoulseekQt. I tested NS, recently, and it also worked fine.

Today, Qt again functions well. So I really don't have any idea. I wish it was more predictable when/if it was going to work correctly. I'm not sure how confident I feel about trying your suggestions (because I'm not a computer/IT expert), but I will keep them in mind. I'm still unsure that the card is the issue because until last year I was using Qt on this computer without any problems for several years. Thank you.

Hi eccles
that's why I wrote "I'd do". That's surely a quite huge troubleshooting. As torrents work like flooding (which is were torrent became famous for). Have you tried older qt versions without problems?
Have you tested the different windows user already (new profile, new empty config files)? SLSKqt is not fully compatible to all it's old settings. The right upgrade path is to export the config with the old Qt Version, then install the new one, import the settings (even when everything was set as it should look like) and restart Qt.

I did try a new Windows user after you suggested it, but that unfortunately didn't help. Where can I find older builds of Qt to download? I think that the last one I used without any problems was from May, June, or July of 2015. I'm not 100% certain.

OK so it's no Config problem as well.
I guess the version U used is: SoulseekQt-2015-6-12.exe; simply search (google, filehippo) for that name;
others are:


Create a environment variable called QT_BEARER_POLL_TIMEOUT and give it a value of -1. Then restart SoulSeek.

I'm not sure how to do that, but I can ask Google. What is the purpose of doing so? Thanks!

Recent versions of Qt are fucking stupid and poll all wired/wireless interfaces constantly, making them lag and even die if the driver is flaky. So you should try that, maybe it helps.

In my case my connection was lagging constantly with Soulseek on, even if it was offline.

Which version of Qt do you think these problems started with? I can always downgrade, there's almost no advantages to the using newer versions of Qt for what SoulseekQt does.

QT_BEARER_POLL_TIMEOUT is a Qt 5.5 feature, I wonder if 5.4 will work better.

Looks great, I'll try it out, thanks.

I think that Sammy is right--the last one I used that had no problems was probably SoulseekQt-2015-6-5.exe or SoulseekQt_04_2015.exe. On my other PC, 2015.2.21 works perfectly. I'm not sure which versions those would be, but those are probably the builds. I'm out of town, now, but I will give these a try in a few weeks and hope for good results. Thank you for your help, as always.

Ok, let's try a Qt 5.4 build first, I'll link to it in a bit. If that doesn't work we'll try 5.3 next. I'm also curious to know if turning off your listening ports altogether will make a difference, you can do that by unchecking 'Enable listening ports' under Options->Login.

Here we go, the 5.4 build, let me know how it works for you: