i would down netxms daemon, then run nxdbmgr -d -f check
restart netxsd daemon, did it fix anything? no? down netxms daemon again.
enter your mysql console, and use the netxms database
then, remove that duplicate entry with a mysql query
delete from netxms.event_log where event_id = 26022462;
exit, 'check' netxms database, restart netxms daemon, if a similiar issue occurs for what seems like infinity, you can repeat, or clear out the table with truncate netxms.event_log