It's impossible to edit styles which are not even linked with protected sheet.
Steps to reproduce:
1. Create new protected sheet
2. Try to Modify any Style (F11 -> Right Click -> Modify...)
* If style is not used in protected sheet, then the new dialog should be shown.
* Otherwise a MessageBox with explanation ("Cannot edit style used in protected sheet. Clone/copy the style.") should be shown.
When trying to remove any Style, we have the same issue like in problem description.
Creating new Styles works but modifying the created one doesn't work.
This is an enhancement request as currently LibreOffice is working as it's designed to work.
Verified on Bodhi Linux, LibreOffice 220.127.116.11 release
Low (there are workarounds, opening a new document allows you to edit styles)
possibly an Easyhack so I'm going to go ahead and mark this also as:
In order to limit the confusion between ProposedEasyHack and EasyHack and to make queries much easier we are changing ProposedEasyHack to NeedsDevEval.
Thank you and apologies for the noise
Migrating Whiteboard tags to Keywords: (needsDevEval)