I use sketch_line a LOT, have it set to my favorite presets. Randomly, this preset will vanish from the program entirely on startup-- leaves a blank spot on right-click palette, nothing under "all presets". Usually returns after a couple restarts. 

Also unable to edit my favorite presets (has nothing to do with tags, it's to do with the "select favorite presets" option under the "tools" menu). After sketch_line vanished, accidentally set sketch in its place, and now sketch_line is back I'm unable to remove a preset from my favorites and replace it with that. 

Reproducible: Sometimes

Steps to Reproduce:
1. Open Krita doc. 
2. Select Tools menu.
3. Select "Select favorite presets..."
4. Add sketch_line and 7 other presets to favorites (doesn't seem to matter which, I also have sketch_chrome and sketch_ink_big and have no issues with those.) 
5. Doodle, save, close doc. 
6. Open and edit doc(s) until sketch_line ceases to exist. Very random, sometimes it vanishes every other day, sometimes a month will go by. 
7. Accidentally stick sketch preset in sketch_line's place
8. Sketch_line reappears after a few restarts
9. Try and fail to remove sketch from favorite presets via Tools/Select favorite presets...

Actual Results:  
"Remove Preset" button greyed out in Select favorite presets... dialogue. Tried selecting sketch_line in Add Preset, tried adding it, tried removing any of the other presets, no responses, not even error messages. 

Expected Results:  
Removed sketch preset and replaced it with sketch_line, and also not forgotten a preset for no particular reason. 

Fujitsu LifeBook TH700 Tablet 2 in 1 PC
Ubuntu 14.04 Trusty Tahr 
Usually running VLC media player, Kazam screencast capture, and Image Viewer while running Krita
-- This combination sometimes causes computer to forget what left-click input does, but still responds to keyboard so I can save my work and give it a time-out