1. Login as admin on a clean instance of XE 7.4.2 (with the default DB) and open http://localhost:8080/xwiki/bin/admin/XWiki/XWikiPreferences?editor=globaladmin§ion=Presentation
2. By default, the color theme is Charcoal. Change the color theme.
3. Now, change the color theme back to Charcoal and double click on Save button.
- You get this error , displayed only if you have other color theme set and you change it into Charcoal: https://up1.xwikisas.com/#PgPaQnG4tQine4c2CZ3_8Q
- If I click once on Save button, I expect to be blocked the 2nd click, like in the case of Install button for extensions.