I managed to set up EasyABC as the default program for .abc files using a stand-alone program called Default Programs Editor - http://defaultprogramseditor.com/
I guess you can close this ticket now.
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Unfortunately I cannot provide a fix. It is hard getting EasyAbc running well on all versions of Windows PC, Linux and Mac.
I managed to set up EasyABC as the default program for .abc files using a stand-alone program called Default Programs Editor - http://defaultprogramseditor.com/
I guess you can close this ticket now.