Thanks, OK, will try to look for double interpretation of extensions.
I regret having allowed my friend to install Windows 10 on my PC. I was happy with Ubuntu...

Similarly, sh3f files aren't imported correctly. It opens them with SH3D, but doesn't add them to .eteks.

While hunting for a Java solution, I noticed that some files were seen as .zip files in one instance (which they technically are), but were (correctly) identified as SH3D files somewhere else.