It seems often that when I'm trying to add a field to change in Mass Edit for Opportunities the input field is not the exact same as the one in Opportunities and I receive this error:
tError: Could not resolve field 'project country' from <apex:inputField> value binding '{!opp.projectcountry}' in page MassEditOpp
Any idea where I could find out the <apex:inputField>?
I was lucky once and found that Opportunity Owner was equivalent to OwnerID but I havent had the same luck twice!