Hello BrozTechnologies! Thank you for your response!
These are the versions we are using:
CRM version: 7.11.18, Sugar Version 6.5.25 (Build 344)
PHP version: 7.3.26
SQL version: MariaDB version 10.3.27
Here is the list of things we’ve done so far:
Enabled permissions for Linux directories
Deleted files and tables associated with an old custom module in CRM directories (although we suspect some files might still be in directories, failed to identify them yet)
Deleted old custom module record from upgrade_history table