SYMPTOM:
"Object with ID 'XXXXXX' and type 33 (ServerDef) is not found in the metadata. it may have been deleted." error message appears when creating a project in a 3-tier project source in Strategy Developer, as shown below:

The data source () has not been initialized The data source (XXXXXX) has not been initialized Object with ID ‘XXXXXX’ and type 33 (ServerDef) is not found in metadata. It may have been deleted.