Symptoms

If you have recently migrated your distributed FlexiCapture 12 architecture with a failover configuration for a database but now your are facing with an issue of unstable work of application server followed by  500 error in the browser (sometimes it is followed by timeout error, but not consistently).

Cause

Failover configuration requeirs special driver and additional parameter in the connection string. 

Resolution

• Stop the Processing Server
• Stop the IIS
• Adjust the FC <connectionStrings> in the C:\inetpub\wwwroot\FlexiCapture12\Server\web.config file for using the installed OLE DB driver (https://docs.microsoft.com/en-us/sql/connect/oledb/download-oledb-driver-for-sql-server?view=sql-server-ver15)
  Example: It should like similar to "Provider=MSOLEDBSQL;Data Source=<SqlServerListenerNameAndOptionalPortNumber>;Initial Catalog=<AbbyyDbName>;Trusted_Connection=<true>;MultiSubnetFailover=True".
  The parameters highlighted in bold are important and need to be changed or added if missing. 
• Start the IIS
• Start the Processing Server