In order to reproduce the bug:
 Start LibreOffice and open Offline Help Dialogue with F1.
 Select tab Find.
 Insert 2 words in Search term. The second word should be directly followed by the special character '#'. Example: “word1 word2#”.
 Click 'Find'. LibreOffice hangs. It's only possible to close LibreOffice with the X in the upper right corner either of the Help Window or of the LibreOffice window itself. Expected: No hanging.
There are more special characters with the same behaviour. I only checked it with '#', '+', ')” and '*'.
Bug occurs with version 6.0.5 (64 bit, Win 10, German keyboard layout).
Bug occurs the first time with version 5.3.0. Hence regression.
Thanks for reporting this issue.
I guess this issue is solved with the new help system in 6.1. Could you please try with LibreOffice 18.104.22.168 from https://wiki.documentfoundation.org/QA/GetInvolved#Test_Pre-releases ?
Adding Olivier to the loop...
Yep, we have new search/filtering methods. Closing.