Meeting import: Import fails (structure level issue?)

[MSoeb]

Description: If a superadmin wants to import a meeting, the import could fail. I guess this is related to the changes of the structure level. Here are examples:

• First example: Structure level error:
  Console failure message : POST https://testintern.staging.openslides.com/system/action/handle_request 400 (Bad Request)
  More Details about the error:
  

• Second example: Import does nothing. After clicking Upload, the upload starts and ends without a response or console error message.
  Ironically, the detailed message in console point to this:
  

The crucial point is, that I can't reproduce the issues. If you need Details and import files to try it, please contact me.

[luisa-beerboom]

Won't fix bc this arises from corrupt databases