QGIS on Windows freezes/slows to an unusable crawl when Browser Panel is open

[scottshambaugh]

Describe the bug

I recently reinstalled Windows 10 v. 1909 on my laptop, and installed QGIS 3.10.1 immediately after. However, the program would take a few minutes to load up, and any action I wanted to do would take anywhere from 30 sec to ~5 min to accomplish. Simple actions, such as clicking on a menu button to open the dropdown, panning the map, even just hovering over something to bring up a tooltip. The program would freeze, after a few seconds would white out and show (Not Responding) in the title bar. After the period of time, the program would unfreeze and complete the last action, only to freeze up again when I tried to do the next one. This was happening for me also when I tried downgrading to the 3.4.14 LTR. Occasionally when I restarted the program I got a few seconds of responsive behavior before QGIS started freezing again, but this issue was persistent.

I found a May 2019 answer on gis.stackexchange by user huha who suggested that closing the browser panel fixed slowdowns for them. I tried X-ing out the browser panel, and after the time delay for the action to complete, the browser closed and everything was immediately quick and snappy again. Startup times were also fixed. This fixed it for me in both 3.4.14 and 3.10.1. Don't see a bug report on github here, so opening one to bring this to attention.

How to Reproduce

Fresh install of QGIS on Windows 10, the issue occurs immediately.

QGIS and OS versions

QGIS version
3.10.1-A Coruña
QGIS code revision
ef24c52
Compiled against Qt
5.11.2
Running against Qt
5.11.2
Compiled against GDAL/OGR
3.0.2
Running against GDAL/OGR
3.0.2
Compiled against GEOS
3.8.0-CAPI-1.13.1
Running against GEOS
3.8.0-CAPI-1.13.1
Compiled against SQLite
3.29.0
Running against SQLite
3.29.0
PostgreSQL Client Version
11.5
SpatiaLite Version
4.3.0
QWT Version
6.1.3
QScintilla2 Version
2.10.8
Compiled against PROJ
6.2.1
Running against PROJ
Rel. 6.2.1, November 1st, 2019
OS Version
Windows 10 (10.0)
Active python plugins
db_manager;
MetaSearch;
processing

Additional context

I don't have the a build set up on my machine for debug output, but I can take a stab at it if it's critical to getting more information.

Laptop is a Lenovo Yoga c930 with 16GB RAM and an Intel i7-8550U CPU @1.80 GHz.

[m-kuhn]

Are there any network drives connected?

[scottshambaugh]

No.

[scottshambaugh]

That did inspire me to try turning wifi on/off and messing with peripherals, and I discovered that this only happens when I have my USB hub plugged in (with at least one further peripheral plugged in to the hub, the issue didn't pop up when I only had the power plugged in). It appears that this shows up at drive E:, which is created for the SD card reader in the hub. However when I don't have a card in the slot, the drive is visible but not navigable, and window's file explorer also times out when I try to access that drive. When I do insert an SD card, the issue goes away.

The error that Windows pops up when I try to navigate to the drive in file explorer is:
E:\ is not accessible.
The request could not be performed because of an I/O device error.

So this looks to be more a bug with Windows / this external device. Though I would still expect QGIS to time out once, rather than continuing to time out on every action, or ideally see that the drive isn't navigable and ignore it.

[ScalingR]

Tracked down the problem and found the solution.
In my Bios was the floppy drive activated. Needless to say that my machine doesnt have a floppy attached. Turned it off in BIOS and QGIS including its browserpanel is running great.

[andreasneumann]

Is @ScalingR the same person than @scottshambaugh ?

Can we close this issue?

[scottshambaugh]

No, we’re not the same person, and no, the bug persists. This sort of missing drive scenario should be something that’s handled more gracefully than bricking the whole program.

[rmarzocchi84]

I have a similar problem. It seems caused by network folder. When I am not connected to the correct network (office or VPN) it give problem to browser and QGIS is not usable

[rmarzocchi84]

It seens connected to this issue #33164

[lhilarides]

I have the exact same issue, i.e. the browser freezes for minutes and startup is very slow, and I don't have any network drives connected as described in #33164 . I do have 3 SSDs , 1 HDD and a USB hub connected so will try to see what happens when I remove those. Nevertheless I feel this is something that should probably be fixed in the QGIS browser, not on all users systems.

[bhollinshead]

I've just experienced the same problem. In my case it was because my BENQ PD3200U monitor (which has an SD slot was registering a removable media drive with windows but I didn't have a card in it so it wasn't showing up in explorer). Putting a card in it made the browser panel work again. Seems like it should definitely not stop if it can't find a drive.

[lhilarides]

I have the exact same issue, i.e. the browser freezes for minutes and startup is very slow, and I don't have any network drives connected as described in #33164 . I do have 3 SSDs , 1 HDD and a USB hub connected so will try to see what happens when I remove those. Nevertheless I feel this is something that should probably be fixed in the QGIS browser, not on all users systems.

I tried disabling the browser in QGIS, which kind of improved things a bit in terms of responsiveness but I've just now disconnected my USB hub (card-reader) and this completely 100% fixed the problem.

[LuisAquatics]

It seems connected to this issue #33164

UPDATE: I FOUND A WORKAROUND,WHICH I POSTED IN #33164 (comment)

Original Post:
I experice the same Problems as descirbed in this threat which points the problem on networkdrives that are disconnected and therefore freeze Qgis.
In my specific case, I use CiscoAnyconnect to connect to University via VPN using a network drive. If the connection is disabled, no startup possible.
If conncection enabled, startup is possible, use is possible but a bit laggy. Within QGIS, no project or file is related to this VPN network drive. When disabling VPN while in QGIS, the programm will freeze at the next action (simple menu button click) until Networkdrive is re-enabled again.

@sdieters this might be interesting for you as similar/same problem discussed in #38346

[guncha]

Same issue here - I had a disconnected network drive and QGIS would freeze for about 15 seconds on every action. Getting rid of the network drive fixed it. Clearly QGIS is doing file operations in the UI thread, or at least it's getting blocked by them, which is.. not ideal. I don't know enough C++ to try to fix it, but let me know if I can help in some other way.

[Marwe]

The workaround from #33164 might help: "hide from Browser" for certain mount points ("drive letter" in Windows). I experienced it under Linux and since a long time, too, so might be a more general issue of the Qt implementation or specific usage in QGIS, that triggers it.

[punkerdood]

Same problem same solution for my Win10 box 64gb ram, 8 core i9. It kept looking in a networked folder for.... I dont know what. I clicked 'hide from browser' and now all is well.

[nyalldawson]

This is fixed for 3.20

[scottshambaugh]

It looks like this was addressed in PR #43416. I just tested it with the 3.19 nightly build and can confirm that the issue is no longer occurring for my missing local drive scenario. Thank you @nyalldawson!

I believe that issues #33164 and #32797 are fixed by that PR and can now be closed as well.

[GregHNZ]

This is back with 3.20

[nyalldawson]

@GregHNZ please try unchecking Settings -> Options -> Data Sources -> "Automatically refresh directories in browser when their contents change"

[rubisco57]

@nyalldawson Deactivating Settings -> Options -> Data Sources -> "Automatically refresh directories in browser when their contents change" does not solve the problem for me in 3.20.3, my only work-around is connecting to the network drive.
Unchecking "Monitor for changes" (Right click -> Scanning) does not help either.

[ignaciobfp]

Still happens on 3.22.1 (fresh installed with Osgeo4W). Hiding network drives solved the issue as described, did not test the other workaround. This was driving me crazy since resource usage was very low but slowdowns were very extreme even with a relatively simple project.

Full details of my current installation (it is installed on a notebook with O.S. windows 11 21H2 despite being reported as Win10 2009):

Versión de QGIS	3.22.1-Białowieża	Revisión del código de QGIS	663dcf8
Qt version	5.15.2
Python version	3.9.5
GDAL/OGR version	3.4.0
PROJ version	8.2.0
EPSG Registry database version	v10.038 (2021-10-21)
GEOS version	3.10.0-CAPI-1.16.0
SQLite version	3.35.2
PDAL version	2.3.0
PostgreSQL client version	13.0
SpatiaLite version	5.0.1
QWT version	6.1.3
QScintilla2 version	2.11.5
OS version	Windows 10 Version 2009
Active Python plugins
ImportPhotos	2.2.2
db_manager	0.1.20
grassprovider	2.12.99
MetaSearch	0.3.5
processing	2.12.99
sagaprovider	2.12.99

[GeoKeys]

Version 3.24.3-Tisler has the same problem but hiding disconnected drives from QGIS browser solved the issue.

[GGDRriedel]

This is back for me on 3.26.2 , no network drives connected.
Can't browse ANYTHING.

basically, the program is unusable

[alexhorn]

This is fixed for 3.20

Unfortunately this does not appear to be fixed in 3.28.2.

[pedrocamargo]

I have the impression that this is related to security settings on Windows, as I have been able to reproduce the change in behaviors by turning all security settings off on Windows.

[Twaart]

Running v3.22.5 But this behavior has been seen since I started using QGIS (3.15)
I have several connections to different Postgis DB behind a VPN.
Here are some observation I've made.
No matter haw many connections my project has 0 or n, Qgis freezes for an undetermined amount of time (usually counted in minutes) if the browser panel is open.

WMS/WMTS Layers do not freeze QGIS if they loose connection (i.e. loss of WIFI)
All layers coming from either Network drives or DB will cause a freeze is data is no longer reachable.

[GGDRriedel]

Same. It doesn't occur when my VPN is open,
When it is closed , I can't use any browser. I do not have any of the folders in any favorites or anything

[DGMaxime]

Same problem with a Synology NAS. I'm connected to my NAS by connecting network drives (relative to folders on my NAS). But when the NAS is turned off and inaccessible, Qgis freezes very often, with each focus and even while keeping the focus. It freezes for several seconds each time. And, importantly, it only freezes when the browser panel is displayed. I think the browser panel is trying to establish the connection to the inaccessible network drive.

Solution: delete my network drives, or no longer use browser panel.

[jo-chemla]

Thanks for pointing out this might originate from network drives, I had the same problem and ended up removing the Browser Panel from qgis to avoid such freezes. Removing the network drives might be a good temporary fix while this bug is present.