Eli/Andreas,
Here are a few more things I tried.
1. Removed the current libotf and libm17n-flt libraries, installed the versions
libm17n-flt 1.6.4-2ubuntu1
libotf0:amd64 0.9.13-3
Configured and compiled emacs. This crashes as well.
2. If I set the default font to Noto-Kannada and open the file, It has no issues but crashes as soon as I start adding English words.
3. The crash occurs only when a certain combination of Kannada chars are present along with English characters/Words.
Let me know if you need additional data.
There were no such issues with a variant of ubuntu-14.04.
Regards,
Reddy