When two simultaneous writes to the same database table occurs, a deadlock may occur with the following message.

2020-09-08 13:15:03.004 INFO - 
RefreshDataStore.DefaultExtendedDataSource.reconnectNativeConnection - 
Reconnecting 1  clientConfig.xml because of 
java.sql.SQLRecoverableException: org.firebirdsql.jdbc.FBSQLException: 
GDS Exception. 335544336. Deadlock

1. If debug is enabled we should be able see which statement caused the problem. See also How to help us to support you.
2. Our software normally autorecovers from this situation. It will attempt up to five times repeatedly to complete the write action that failed the first time. This is a feature.
3. The usual cause of this is a slow disk where the firebird datastore is located or some network slowness (latency) causing the simultaneous writes to lock the database table longer.
4. There are various other reasons why recovery exceptions may occur and we prefer to always log the reason because then we can decide it is a problem or not.
5. If the autorecovery fails, a stacktrace appears indicating which write action has failed. If a stacktrace occurs even with the latest patch.jar, a bug report can be sent to Delft-FEWS Support.