KB-1295 "An unknown error has occurred while saving the process model" thrown when saving a process model

Symptoms

When attempting to save a process model, an error message “An unknown error has occurred while saving the process model” appears and the changes to the process model are not saved:

An unknown error has occurred while saving the process model.

A 500 error can also be observed in the browser capture indicating the request was not successful.

Cause

A 500 error indicates an internal server error; that there is a misconfiguration at the Apache level. This error prevents the request from completing successfully.

Action

For non-production environments: stop Apache. Disable mod_security in httpd.conf on Apache to allow the requests to go through. Restart Apache. Once you confirm the root cause, fix the conflicting mod_security rule.

Caution: Disabling mod_security could potentially be dangerous for some systems. Please confirm with your Web Server Administrator before making any changes. Refer to Apache Docs for more information.

For production environments: make adjustments to the mod_sec rules based on the Apache logs.

Affected Versions

This article applies to all versions of Appian using Apache as a web server.