התקנת דיסקוס נכשלה עקב תוסף Custom Wizard

Actually I think the error is right there.

It looks like you are trying to build with two versions of the same gem. Hence: Gem::LoadError: can't activate request_store-1.5.0, already activated request_store-1.5.1

You need to ask the plugin maintainer using the older version if it’s possible to update to the same version and then they might happily coexist.