When attempting to open a project, the error: "500 - Internal Server Error..." is shown in the GUI.
Looking at the app_ca.log file after reproducing the issue, we see the following:
Error message: [CA Clarity][Oracle JDBC Driver][Oracle]ORA-00904: "ODF_CA_INV"."NAME_OF_CUSTOM_ATTRIBUTE": invalid identifier
The PPM Health Report also shows "Invalid Database Objects" as a warning.
Although the exact cause of this error is not known, it could happen due to rogue data in that field pointing to values that do not exist.
Workaround: Deactivate the attribute identified in the log error, and then attempt to access the project again. This should allow you to get to the project without a problem.