Compare the 2 .aird file using "Compare with / each other" in the left hand corner of the diffmerge editor, click the drop down menu and select "Text Compare" java.lang.NullPointerException: Cannot ...

DiffMerge was getting killed on my mac. It turns out a hacky fix (martinsson@01dc6ea) will to the job. I'd be happy if someone had a better grasp of why this is so. But if we don't understand perhaps ...