libreoffice crashing after editing index entry

The problem I have is with Writer. I am using OS X El Capitan and Version: of Libre. Language always in English for both. I have already checked some posts, also on the Open Office website. I didnt find the solution so far but. Please help me, I am trying to get my master thesis done in time. About a week ago I had the problem that Libre Office and Open Office hept crashing. Now that seamed to have resolved (before it was going in a loop and kept crashing,couldn’t even get into it).But I realised now that I cannot edit the INDEX ENTRIES, Libre Office just crashes. No error messages. I can however enter new entries for the table of contents. In open office it works.
Before I also tried to remove bottons from the Toolbar (like Formula etc.) and it crashed again, No error message as it crashes and it also doesn`t save it properly, so I keep having to save constantly out of paranoia to lose all work again.

[edit: removed back-tick that was causing strange formatting]

This is a known bug. See I upgraded to, but now I see no way to edit index entries on new documents. It is present on existing documents with index entries.