Bug 514684 - Components can be loaded from old invalid cache version after upgrade, breaking widgets
Summary: Components can be loaded from old invalid cache version after upgrade, breaki...
Status: CONFIRMED
Alias: None
Product: libplasma
Classification: Frameworks and Libraries
Component: libplasma (other bugs)
Version First Reported In: 6.5.90
Platform: Fedora RPMs Linux
: VHI normal
Target Milestone: ---
Assignee: Plasma Bugs List
URL:
Keywords:
: 514720 514839 514894 (view as bug list)
Depends on:
Blocks:
 
Reported: 2026-01-16 10:51 UTC by greg.moxham
Modified: 2026-01-21 14:45 UTC (History)
9 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
Screenshot of error state (44.20 KB, image/png)
2026-01-16 10:51 UTC, greg.moxham
Details
Kinfo (274 bytes, text/plain)
2026-01-16 10:51 UTC, greg.moxham
Details
qmlcache.bk.zip (2.21 MB, application/zip)
2026-01-17 22:09 UTC, jv
Details

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Description greg.moxham 2026-01-16 10:51:07 UTC
Created attachment 188580 [details]
Screenshot of error state

SUMMARY

Just updated to Plasma 6.5.90 on Fedora 44 (Rawhide).

Rebooted and passed the login screen, then presented with an error screen which states:

Sorry! There was an error loading Folder View.

Then the following:

file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/main.qml:379:17: Type FolderView unavailable

file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/FolderView.qml:556:13: Folder.RubberBand is not a type

STEPS TO REPRODUCE
1. Update Fedora 44 Rawhide to Plasma 6.5.90 using package manager
2. Reboot
3. Log in

OBSERVED RESULT

Desktop does not load. Error screen displayed. Unable to dismiss.

EXPECTED RESULT

System loads desktop environment.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 44 Rawhide
KDE Plasma Version:  6.5.90
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Struggling a little to add info to the bug due to being locked out of desktop. Will add more details as I'm able.
Comment 1 greg.moxham 2026-01-16 10:51:38 UTC
Created attachment 188581 [details]
Kinfo
Comment 2 greg.moxham 2026-01-16 10:52:21 UTC
Operating System: Fedora Linux 44
KDE Plasma Version: 6.5.90
KDE Frameworks Version: 6.22.0
Qt Version: 6.10.1
Kernel Version: 6.18.0-65.fc44.x86_64 (64-bit)
Graphics Platform: offscreen
Processors: 18 × Intel® Core™ Ultra 5 125H
Memory: 16 GiB of RAM (15.1 GiB usable)
Comment 3 greg.moxham 2026-01-16 11:06:05 UTC
It's probably bad practice and a bit brute force, but removing ~/.cache/plasmashell/qmlcache and rebooting solved the issue.

Obviously this removes personalisation settings.
Comment 4 Colin J Thomson 2026-01-16 14:12:15 UTC
(In reply to greg.moxham from comment #3)
> It's probably bad practice and a bit brute force, but removing
> ~/.cache/plasmashell/qmlcache and rebooting solved the issue.

I had the same issue and clearing the cache fixed it for me, thanks for the tip.

FWIW I did find initially if I ran system settings from Krunner and set  my Layout to Desktop and not Folderview it got me back to a more usable system, but then of course I had no Icons on the Desktop.

I am running the beta from the kde-sig COPR.
Operating System: Fedora Linux 43
KDE Plasma Version: 6.5.90
KDE Frameworks Version: 6.22.0
Qt Version: 6.10.1
Kernel Version: 6.18.5-200.fc43.x86_64 (64-bit)
Graphics Platform: Wayland
Comment 5 cwo 2026-01-17 09:04:45 UTC
*** Bug 514720 has been marked as a duplicate of this bug. ***
Comment 6 jv 2026-01-17 20:12:55 UTC
Bad bug!
OS: Fedora Linux 44 (KDE Plasma Desktop Edition Prerelease) x86_64
Kernel: Linux 6.18.0-65.fc44.x86_64
KDE Plasma 6.5.90


-logged in on another desktop and made a backup of ~/.cache/plasmashell/qmlcache
-then deleted this folder.
-rebooted and logged into KDE plasma 
-all desktop icons as well as symlinks workiing as before.

much thanks to the previous reports!
Comment 7 Nate Graham 2026-01-17 20:37:10 UTC
Thanks for saving the old bushed cache. That will help troubleshooting. Can you attach it?
Comment 8 jv 2026-01-17 22:09:29 UTC
Created attachment 188628 [details]
qmlcache.bk.zip

Attached.


On 2026-01-17 3:37 p.m., Nate Graham wrote:
> https://bugs.kde.org/show_bug.cgi?id=514684
>
> Nate Graham <nate@kde.org> changed:
>
>             What    |Removed                     |Added
> ----------------------------------------------------------------------------
>       Ever confirmed|0                           |1
>               Status|REPORTED                    |CONFIRMED
>
> --- Comment #7 from Nate Graham <nate@kde.org> ---
> Thanks for saving the old bushed cache. That will help troubleshooting. Can you
> attach it?
>
Comment 9 Antonio Rojas 2026-01-19 20:32:22 UTC
*** Bug 514839 has been marked as a duplicate of this bug. ***
Comment 10 Antonio Rojas 2026-01-21 11:35:43 UTC
*** Bug 514894 has been marked as a duplicate of this bug. ***
Comment 11 tempqd 2026-01-21 12:20:38 UTC
Ah, can confirm removing ~/.cache/plasmashell/qmlcache remedied it for me too. I guess it was loading an old version of widgets (my plasma-nm tray icon has been having similar issues), and the lines in the error message for Folder View match changes in recent commits.

> Obviously this removes personalisation settings.
Which ones? I don't immediately see anything different but now I'm nervous.