Recently I migrated on new hosting where the Suite with installed plugin v1.0.1 gave HTTP 500 error.
When I tried to reinstall the plugin installation failed every time with the error: 'Sorry, you do not have permission for that! 1S111/1'. A permissions for newly created files and folders were 644 & 777 respectively, they were correct. Previous version 1.0.0 installed just fine.
I made some research with Get Ready For IPS script and found the cause. It was in suhosting PHP extension values below then recommended ones. Here they are:
suhosin.post.max_vars >= 4096
suhosin.request.max_vars >= 4096
suhosin.get.max_value_length >= 2000
suhosin.post.max_value_length >= 10000
suhosin.request.max_value_length >= 10000
suhosin.request.max_varname_length >= 350
After adjusting mentioned settings plugin was successfully installed and run