hi forum

we have some errors in our z-push log:
29/05/2017 16:02:11 [19001] [FATAL] [username1] WBXML 10K debug data:
29/05/2017 16:02:11 [19001] [FATAL] [username1] Exception: (StateInvalidException) - Unexpected synckey value oldcounter: '487' synckey: '{094af015-a3c9-4cff-b6d7-e20cbd08f6d2}488' internal key: '{094af015-a3c9-4cff-b6d7-e20cbd08f6d2}'

29/05/2017 16:02:54 [21375] [ERROR] [username2] HandleSync(): error saving '{9772bee3-cd10-48db-9efe-08832ca93d8e}1' - no state information available

os: debian 7.11
kopano version: 8,4,0,347
z-push version: 2.3.6+


any suggestions for that errors?

thanks in advance.

regards,
daniel