To solve the problem delete the PUID parameter from the DBID.xml file and let ALM to generate a new project UID.
These are the steps to follow:
1. Remove the project from Site admin.
2. Browse to the project repository.
3. Edit the DBID.xml and delete the PROJECT_UID parameter.
4. Save the file.
5. Restore the project.
A new PUID would be generated.