Before following along with the steps below, I recommend that you make a copy of the project repository and store it in a safe location just in case any unforeseen issues occur. 
The process listed below will create a new, valid Project UID and populate the value in other areas of the site admin and lab project.
 - REMOVE the affected project from Site Administration.
 - Open the project's ''dbid.xml'' file so you can edit the PROJECT_UID field.
 - Delete the value displayed in the PROJECT_UID field.
 - Save the changes made to the ''dbid.xml'' file.
 - RESTORE the affected project in the Site Administration.
After you have completed the process, log into the project and make sure everything looks and functions as expected.
I hope this helps!