If you receive an "Error 500: Internal Server Error" on a website it may be due to the CloudLinux Quota.
To confirm if this is the fault:
- log into the cPanel and check the Memory usage
- If it is full you will need to search 'Limit' in WHM
- Select 'CloudLinux LVE Manager' from the list
- Select 'Edit Settings for Specific LVE'
- Enter the account username and select the memory the account requires