The application server fails to start with the following error in the application server log:
ERROR com.appiancorp.common.config.ConfigObject - An error occurred while trying to initialize the config object com.appiancorp.type.config.plugin.PojoDatatypesConfig
Cause: An error occurred while trying to save the type information to the Appian data source. No types have been imported. Cause: No DatatypeModel was found for any of the following ids to be updated: ##EXTERNAL IDS AND APPIAN ERROR CODE##
The cause for this is that primary database (specifically the DT_MODEL table) is out of sync with the design engine. This mainly happens during upgrades when the migration of the engine database files (*.kdb) is done incorrectly. This could be if you are using older files to perform the upgrade. This could also happen if you are switching primary databases (unsupported), tampered in some way with that table or pointing it to a brand new database on the new version even though you are migrating from a previous version.
If the database has been tampered in some way in the past, the error would show up during migration, and not on an application server restart. This would happen because the design engine attempts to synchronize with the primary database specifically after a migration.
Query the DT_MODEL table to see if the ID is present in the primary database first. If it is not present or if the namespace of the row is not http://www.appian.com/ae/types/2009, then it is a clear indication of a problem. If this is a migration, make sure you are using the latest engine database files (*.kdb) for all engines. You can checkpoint the engine in the old system to get the latest database file (pd_*.kdb) to attempt the upgrade again. If it is determined to have been caused by a tampering, the best way is to recover from a backup.
Another way to proceed is to start over with a fresh installation and import all applications from the old installation. However, all data would be lost, meaning this is only recommended for development and test environments.
If you determine that all of the upgrade steps were followed correctly and there are no inconsistencies between the engine and DT_MODEL table then this could be a race condition during propagation of data types after the migration. A restart of the application server should fix this issue.
This article applies to all versions of Appian.
Last Reviewed: February 2017
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