500 error when assigning leads

I’m assigning 1000 leads to another user. First the process gets stuck because SuiteCRM tries to send a separate email for each assigned lead to the user (why??). After disabling that in the Email options i still get a 500 error after a couple of minutes and when checking the suiteCRM log i see this:

Thu Jul 19 09:16:40 2018 [3026][1][FATAL] log call at: modules/Administration/index.tpl:54 - MY_FRAME is not set

When loading the Leads page again i see 990 out of 1000 leads were assigned to the user.

Hi! What is your SuiteCRM version?

That error is probably not related. Any way it has been fixed, you can apply the fix manually:

https://github.com/salesagility/SuiteCRM/pull/6097/files

I would look at your php.ini settings and give more generous values to

memory_limit
max_execution_time

Remember to restart web server.