<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Work on this issue](https://contributors.gitlab.com/manage-issue?action=work&projectId=278964&issueIid=460839) - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=460839) </details> <!--IssueSummary end--> As suggested in https://gitlab.com/gitlab-com/dev-sub-department/section-dev-request-for-help/-/issues/242#note_1897111619 we should add some error handling in [MentionsCoverter](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/import/mentions_converter.rb) so that the import isn't blocked by non-blocking logic.