Hi, We are getting the following error in one of our environment.

It seems that at some point the DT_MODEL table of this environment was wiped out or the environment was reverted to a previous date but the the primary data source doesn't match that timestamp.

Since you are running Appian 6.6.1 this is what you can do:

1. Create an application and add the data store. Use the check missing dependencies to add the required data types. Do you see the data store is pointing to old CDTs? like MYCDT^1?
2. If not, then export the application and review the export log to determine what CDTs are the problematic ones
3. Delete those CDTs from the Data Management tab and reimport them
4. Update your Data Store via Impact Analysis or manually to point to the new version of the CDT instead of ^1 (DO NOT DELETE ENTITIES NOR THE DATA STORE just use Impact Analysis or manually remap but don't delete anything)
5. See if you can now verify the data store.

If you still can't:

1. Stop the application server
2. Comment out the primary DS in custom.properties

#conf.data.primary.datasource=xxxxxx

3. Start the application server
4. Delete the problematic CDTs again
5. Reimport the CDTs
6. Stop the application server
7. Uncomment the primary DS
8. Start the application server
9. This should have assigned new local and external IDs to these data types. Just remap the data store so it points to the latest version of the CDTs(DO NOT DELETE ENTITIES NOR THE DATA STORE just use Impact Analysis or manually remap but don't delete anything)
10. Validate the data store.

It seems that at some point the DT_MODEL table of this environment was wiped out or the environment was reverted to a previous date but the the primary data source doesn't match that timestamp.

Since you are running Appian 6.6.1 this is what you can do:

1. Create an application and add the data store. Use the check missing dependencies to add the required data types. Do you see the data store is pointing to old CDTs? like MYCDT^1?
2. If not, then export the application and review the export log to determine what CDTs are the problematic ones
3. Delete those CDTs from the Data Management tab and reimport them
4. Update your Data Store via Impact Analysis or manually to point to the new version of the CDT instead of ^1 (DO NOT DELETE ENTITIES NOR THE DATA STORE just use Impact Analysis or manually remap but don't delete anything)
5. See if you can now verify the data store.

If you still can't:

1. Stop the application server
2. Comment out the primary DS in custom.properties

#conf.data.primary.datasource=xxxxxx

3. Start the application server
4. Delete the problematic CDTs again
5. Reimport the CDTs
6. Stop the application server
7. Uncomment the primary DS
8. Start the application server
9. This should have assigned new local and external IDs to these data types. Just remap the data store so it points to the latest version of the CDTs(DO NOT DELETE ENTITIES NOR THE DATA STORE just use Impact Analysis or manually remap but don't delete anything)
10. Validate the data store.