[cromag]

I have used Abiword when I needed to run Linux on very old hardware. Abiword is a good word processor, but it's designed for systems that have limited resources -- there's no reason (I can think of) for having both Abiword and LibreOffice on the same computer. If you can run LibreOffice without problems I'd uninstall Abiword. (If it turns out you do need to have Abiword too, you can always re-install it -- it's free.)

I've never used highlighting but it's entirely possible that a given feature would be implemented differently with two different applications. You can keep Abiword from opening as eschwartz described, but make sure you hit all the word processing formats you might use, like .doc, .docx, etc.

But, honestly, my first recommendation would be to uninstall Abiword and see if that helps.