linux - Debugging ExtFS on OSX - works for 3 days then nothing?

I installed the trial of ExtFS 9.7.109 on OS X 10.10.3. It worked great for the first 3 days. But now my ext4 drives no longer show up.

Last thing that worked was copying data from an ext4 drive. Strangely, folders moved in Finder were not complete. The ext4 drive showed files not moved. I tried a few times again and eventually it was fine. But on the next reboot the two ext4 drives disappeared.

I do not suspect the drives as Diskutil can still see them. Also, installing OSXFuse also works fine. I can copy data that way. But no write of course.

I tried reinstalling ExtFS several times but nothing works.

I looked in the console but saw no errors from ExtFS.

How do you suggest going about debugging this?