Exclude value from the list of values of Affected Version field only on create issue screen

[helen levich]

While creating new issue for issue-type "Bug"  users sometimes pick "Backlog" as Affected Version. That is inappropriate value for new "Bug" issue. We want to have "Backlog" value available for Affected Version field, but not when issue type "Bug"  is created. 

Practically we want to exclude "Backlog" value from under Affected Version only on create issue screen for "Bug" issue type.

We can't use ScriptRunner (Simple Validator) because there is bug in ScriptRunner while used with Affected Version field. When we setup Simple Validator it gives error on picking any value in Affected Version field. We tried to address bug with Adaptavist, but they could not help us because we are on older version of ScriptRunner

Any suggestions will be greatly appreciated. Thank you