Screenshot two: After right clicking on the bookmarks and choosing “Remove Bookmark” (on B - Index Data). Observe bookmark is still present in list. Highlighting is still present in hex.
Can you verify that you are using our latest version 16.0.3 of 010 Editor? There were some fixes in this version related to bookmarks. We cannot seem to replicate the issue with 16.0.3 but if you can get the crash in this version, can you please do some more investigation and figure out exactly which steps are needed to replicate the crash? Thanks!