Explanation
A before save flow trigger is a type of flow that runs before a record is saved and can update the record without any additional actions or database operations. This can expedite the time required to update the records and improve performance. A before save flow trigger can be used as an alternative to a process builder that updates the same record that triggered it. References:
https://help.salesforce.com/s/articleView?id=sf.flow_concepts_trigger.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.flow_ref_elements_triggers.htm&type=5

Explanation
To resolve the issue with the Process Builder, the administrator should do the following steps:
Review the Error Email for the Process Builder and rectify the issues. The error email contains information about what caused the error and how to fix it.
Deactivate the Process Builder in production. This will prevent further errors from occurring while the administrator fixes the Process Builder.
Fix the Process Builder in a sandbox and migrate the change to production. This will ensure that the Process Builder is tested and validated before deploying it to production. References:
https://help.salesforce.com/s/articleView?id=sf.flow_troubleshoot_error_email.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.flow_deploy.htm&type=5