Issue with Pop up for Version 7.4.3

I am finding I am getting a 404 error when trying to open a pop up for the following:

index.php?module=Accounts&action=Popup&mode=single&create=true&field_to_name[]=name

It works for some but not all of the modules. Like:

index.php?module=Project&action=Popup&mode=single&create=true&field_to_name[]=name

Works just fine. However in the Create Meeting and I specify the Related to all give 404 except Project.

Any one know the reason and how to fix?

Might be a PHP version issue with empty parameters or something, I’m getting a 500 each time I try to use the geocoding feature.
Still haven’t found the time to figure it out