Steps to reproduce:

1. start clean and fresh instance
2. create 10000 hosts
3. apply template to this hosts and try to import updated version of the same template
4. get in the log:

   2023/05/30 10:15:37 [error] 19#19: *13 FastCGI sent in stderr: "PHP message: PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted
   

Result:
Import window keeps animation in progress.

Expected:
Catch backend PHP errors and provide useful information in frontend.