Starting yesterday, I noticed bulk uploading issues with an assignee listed has started giving the error "Issue can't be created due to the error/s [User '...' does not exist.] with a number that looks like maybe a GUID as the username.
This is using their username as we have done in the past. I've seen several posts indicating Jira cloud will be deprecating usernames but no reference to what to use instead when importing issues.
I tried also using an email address and @ handle as listed in the users' details page, both give the same error.
Any idea what might be going on? Is there a new identifier to use in this case instead of a username or email?
