Icons not appearing on Sitecore Experience Editor
Issue :
On content management server, when you open the experience editor you notice that the ribbon menu icon is not appearing and sometimes the design is broken.

Cause :
Not enough disk space on the server.
In my case, i have some PowerShell Scripts generating backup packages on the fly. Before launching, the script creates a backup of the items before modifying them (for rollback if needed).
The issue, i forgot to do the cleanup, so my disk space has been saturated.

Solution :
- Ensure that you have enough space on you Sitecore server. Generally, the app data folder is among the most space consuming on the server so go to the folder app_data/package and delete unused .zip files.
- Go the path sitecore\shell\client\Sitecore\Speak\Ribbon\Assets\Sprites\Ribbon And remove all files. No worries, files will be re-generated by sitecore.
- Don’t forget to clear sitecore cache and another type of cahe if you have.
Enjoy 🙂