After upgrading to 2.0.2.1_beta_2017-08-01 on synology I am getting the following error:
[ERROR] FATAL UNHANDLED EXCEPTION: System.Exception: Failed to parse the segment: f, invalid integer
at Duplicati.Library.Utility.Timeparser.ParseTimeInterval (System.String datestring, System.DateTime offset, System.Boolean negate) [0x000c4] in <1cb5198b00f34ae59d97ee7fe7a3a16c>:0
at Duplicati.Library.Utility.Timeparser.ParseTimeInterval (System.String datestring, System.DateTime offset) [0x00000] in <1cb5198b00f34ae59d97ee7fe7a3a16c>:0
at Duplicati.Library.Utility.Timeparser.ParseTimeSpan (System.String datestring) [0x0000a] in <1cb5198b00f34ae59d97ee7fe7a3a16c>:0
at Duplicati.Library.Main.Options.get_RetryDelay () [0x00045] in <118ad25945a24a3991f7b65e7a45ea1e>:0
at Duplicati.Library.Main.BackendManager.ThreadRun () [0x002b4] in <118ad25945a24a3991f7b65e7a45ea1e>:0
at System.Threading.ThreadHelper.ThreadStart_Context (System.Object state) [0x00017] in <8f2c484307284b51944a1a13a14c0266>:0
at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x0008d] in <8f2c484307284b1a13a14c0266>:0
at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00000] in <8f2c484307284b51944a1a0266>:0
at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) [0x00031] in <8f2c484307284b51944a1a13a14c0266>:0
at System.Threading.ThreadHelper.ThreadStart () [0x0000b] in <8f2c484307284b51944a1a13a14c0266>:0
This is during parsing of advanced parameter retry-delay, that gets messed up with send-mail-from and send-mail-to when setting up with web interface, but that is a separate issue.
The important thing is that parsing a value from the database for that backupset results in an unhandled exception.
the value should have been 30s but was fs02@…
This might be the occasion to check if any other unhandled exceptions might arrive when reading from the “untrusted” database 
Way to repeat:
Put a non integer in the retry-delay parameter for a backup set.
Expected result:
A message saying that there is a problem, or perhaps even an automatic fix, silent or not(preferable)
What happened instead:
FATAL UNHANDLED EXCEPTION
I have now swapped the values by editing the advanced options by hand using the Edit As Text function, so I am able to run for the time being…
HC