Reason: When upgrading from v6.1 to v6.3, there was a bug in migration script, which was populating the specimen_type for ‘Not Specified’ dropdown values as ‘Not Specified - <Class>’. The actual dropdown value was ‘<Class> - Not Specified’. Due to this, in specimen requirement and specimen table, NULL specimen_type_id was populated. The issue is fixed in 7.0 builds.
...
Run the initial query from the specimen section to make sure there is no specimen_type_id with a NULL value.