LibreOffice toolbar icons went blank after application hanged
Solution 1:
- Open the "LibreOffice" application (not Writer or Calc or any other individual application).
- Go to Tools > Options > View (or press alt+f12 and then select View).
- Select a different option (for example Breeze) in the box next to "Icon style:" and click on OK.
Then Open LibreOffice Writer (or Calc etc.) and see if the icons are visible now. If not, try selecting another "Icon style" following the steps above.