I don't understand why a search in the navigator fails if a single key does not exist (e.g. the issue key changed because the issue was moved to another project).

First of all, the query is actually just a short version of:

issuekey = CORE-123 OR issuekey = CORE-5555

Hence it should return CORE-123 even though CORE-5555 does not exist.

Second, why can't it check it the issuekey changed? We are generating release notes via commit messages and have to translate issue keys that changed all the time and only being able to do so via single issue searches (via quicksearch or REST) is not a solution for us.

A good solution would be to still execute the search but show the warning messages as well!

This does not cover the translation of issue keys, but would help us a lot