[Solved] - Plasma 5.8.0 upgrade - Activities Manager now only shows black thumbnails.

[kdemeoz]

Another bug with 5.8.0: the Activities Manager now only shows totally black thumbnails for each of my Activities, not their actual Wallpapers. Do i need to uninstall then reinstall some component to make it show those wallpaper thumbnails again pls?

[leszek]

It might be a caching issue.
Try going to ~/.cache/ and removing the activityswitcher_wallpaper_preview.kcache file and see if after a relogin it creates correct thumbnails again. (Maybe need to switch to the activities for it to refresh the cache)

[kdemeoz]

(5th October 2016, 13:56)leszek Wrote: It might be a caching issue.
Try going to ~/.cache/ and removing the activityswitcher_wallpaper_preview.kcache file and see if after a relogin it creates correct thumbnails again. (Maybe need to switch to the activities for it to refresh the cache)

Thanks, but it did not help. After deleting that file & logging out/in, KWin/Plasmashell did not properly recreate the desktop [IMO this was unrelated to deleting that file; for the past couple of days Plasmashell has been a bit unstable again with a few crashes], & before i then fully rebooted, i noticed that the Activity Manager previews were still black, & that file had not been recreated in .cache. After rebooting,my desktop was good again, but still the Activity Manager previews were black, & that file had not been recreated in .cache. Bummer.

[kdemeoz]

A bit more info, FYI.

This morning, in one of my Maui VM's [which run as Guests in VB in my Host Maui OS], i found i could make the Activities Manager wallpaper thumbnails return simply by, in each respective Activity, changing the current desktop wallpaper --- then the A/M seems to "notice" it & show it ok. Encouraged, i then tried that same trick in my "real" Maui OS... but sadly it made no improvement.

Of course, my real Maui still has no activityswitcher_wallpaper_preview.kcache file in ~/.cache/ anymore [it's still sitting in the waste bin]... i wonder if i should undelete it then repeat this trick?

[leszek]

Yeah just try it. I still think it has todo with the cache.

[kdemeoz]

I tried it ... still broken. I now rather suspect this bug might be directly related to my #7 at https://forums.mauilinux.org/showthread.php?tid=24001&pid=39529#pid39529

[kdemeoz]

Any more ideas for me to try pls? This morning Maui received another big batch of updates, but afterwards sadly the Activities Manager persisted with the blank black thumbnails, rather than the actual respective wallpapers.

[kdemeoz]

https://bugs.kde.org/show_bug.cgi?id=370447

[leszek]

Maybe this fixes it: https://quickgit.kde.org/?p=plasma-desktop.git&a=commit&h=f49216b7211026bfb08d8152a1e5ff2beb02208f

Its a patch that is already in the new Plasma 5.8.1 version that came out today.

[kdemeoz]

Ahhhhh, interesting! If you followed my recent link to the bugs.kde.org entry i raised for this problem you'll have seen that Ivan wrote to me last night & i replied to him today. It seems he's moved nice & fast on this, which is quite pleasing!

I followed your link, but i don't really understand the information. Is there anything on that page that tells me what i can do now, or [as i suspect from your post] i instead need to wait til Maui gets the 5.8.1 update?