[rules-users] Question on Drools upgrade from 2 to 5

Hi, We are an insurance company employing drools ( version 2 currently) for policy validation rules and for reading policy specific rates from spreadsheet using drools. We are currently running in to memory issues when we execute the compiled JAR ( including the drools compiled files), as there are lot of rules fired for different versions of policy rating. My question here is :- Is there any scope of resolving this memory issue with upgrade of drools package from version 2 to version 5? Will the compiled DRLs in Drools 5 be more compressed compared to Drools 2? I have been trying to upgrade to Drools 5 by adding the necessary jars for compilation. But unfortunately I am gettng few errors on spreadsheet and DRL compilation. Is there more to work on the upgrade? One of the errors I frequently get for spreadsheet comparison is something like below: *Invalid character input "?" (character code 65533)* Please clarify my above questions. Thank you much, Steve **