Error in contributor

[EP_explorer]

Sometimes I receive a message of error when I open Hierarchy of approval in Conributor apllication (version 10.1)

sort of:
http://servermame/PMPSVC/Services/json/pmpservice status:500

It is not critical usually because when I refresh IE it disappeares and I can see approval hierarchy again.
But it is nuisance thing and I don't want to see it at all.

It seems that Contributor application are loosing connection with the TM1 server. May be some parameters of timeout (which check connection between Contributor application and TM1 server) exist somewhere which are too small.