Hi Eli
I have the same setup, and got the same problems with the 375 release. We think that it is a problem with the libraries that PixInsight is using in the new release, instead of the system's ones (to "avoid" compatibility issues...).
Well, to run PixInsight you'll have to edit the .sh file:
#!/bin/bash
appname=`basename $0 | sed s,\.sh$,,`
dirname=`dirname $0`
if [ "${dirname:0:1}" != "/" ]; then
dirname=$PWD/$dirname
fi
LD_LIBRARY_PATH=$dirname
export LD_LIBRARY_PATH
$dirname/$appname-bin $*
This change avoids using those new libraries, and calls the binary file bypassing the launcher. If you don't call the binary, but the launcher, it may work too (don't add "-bin" at the end of the last sentence).
Now, run the .sh, and it should work