I did a fresh install of Leap 15.2 (KDE desktop), logged into my account, and discovered the icon for the Activity Manager is not visible when these icon these themes are used:
Adwaita
Crystal SVG
High Contrast
Oxygen
In place of a visible icon is a blank space. Quite confusing at first.
How I can get my Activity Manager icon back when using the Oxygen icon theme?
I’m using “breeze”. And I do not see the activity manager icon.
To be honest, I had not even noticed that it was missing until I saw your post.
I am not having any problems with activities. Switching activities with the mouse scroll wheel is working as usual. Switching with the keyboard (that windows key + TAB) is working. And ALT-A ALT-D is working.
On my system using the Oxygen icon theme, the “ghost button” where the Activity Manager icon should be functions properly, the same as if the Activity Manager icon was visible.
I just want to get my Oxygen Activity Manager icon back and visible like it was in Leap 15.0 (the version I had on Friday).
There must have been an update to the Breeze icon theme, because when I am using that on my system the Activity Manager icon is visible.
I have this problem, too, on more than 1 PC.
Is there any way to fix this manually?
The problem exists because there is no file “activities.svg” located in “/usr/share/icons/oxygen/22x22/actions/”.
The solution is to copy the file “/usr/share/icons/oxygen/scalable/actions/activities.svg” to “/usr/share/icons/oxygen/22x22/actions/” as the root (administrator) user.
Reported back in March 2020 “Missing/invisible activity manager icon when using oxygen theme” https://bugs.kde.org/show_bug.cgi?id=419086
The Oxygen Icon set is still, AFAIK, (semi) maintained - I guess it’s a low priority fix …