What you could try is: introduce a condition (validator) to your workflow. When your users try to enter the "closed" status, the validator should check if the issue has at least one Excel attachment, and possibly check its filename, etc.
The Script Runner allows writing custom validators in Groovy, and it really should not take more than 10-15 lines of code: https://jamieechlin.atlassian.net/wiki/display/GRV/Validators
It's officially Tuesday, which means it's officially time for another tip to help you better navigate this space we call the Atlassian Community. 😄 I got a great question from community member, Sa...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs