Formula boxes become blank after saving

I started working on a new document, and after a few minutes I saved my first copy in .ODT format. After another minute or two I scrolled to the top of the document and many (but not all) formula boxes are blank and missing all data.

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This isn’t the first time this has happened, but it has been incredibly rare. I’ve been able to write several lab reports without errors since the first time it happened about 2 months ago.

I’ve tried re-opening the file, and I’ve tried exporting to PDF to see if the equations would show up there, but no luck. I don’t know if it’s relevant, but I’m using it on linux mint 18.

Recovering the data isn’t important to me as there are only a couple which I can easily recreate at this point. I’m just concerned about fixing the problem so I don’t accidentally turn in a report with a missing equation that I didn’t spot.

Thanks ahead of time