The project encounters unforeseen technical issues during release.

In the event of unforeseen technical issues during a release, the most appropriate response is to communicate transparently with stakeholders about the issues and to have a rollback plan ready if necessary. This approach ensures that all parties are informed and prepared to revert to the previous stable version if the new release proves to be unstable or problematic, maintaining trust and system reliability.

References: https://help.salesforce.com/articleView?id=sf.release_manage_best_practices.htm