When some parameters are used in expressions the parameters' order in which they were created metters! If the expression, which contains Param1, is used in Param2 and in parameters the Param2 stays before Param1 then this expression will not work, because Param1 isnot existed. I personaly think that this is like a flow and should be corrected. Moreover, this peroblem doesn't exist in JasperStudio, just on server.