After that I deleted all files from Ruleset folder and repeated.
There is no "Ruleset" folder in the nightlies... so I assume you have just taken 1.0 data files and mixed them with nightly executable... this will not work!
Please do a clean install:
1. backup what you think you need
2. delete EVERYTHING from /home/martin/.local/share/openxcom/
3. delete EVERYTHING from /home/martin/.config/openxcom/
4. I don't know what you have in /home/martin/X-Com/Nightly/ but if it is the 1.0 data files then delete EVERYTHING from there as well... and copy the nightly data files there (they are in 2 subdirectories "common" and "standard")
5. run
This is exactly my situation. Any solution to run both version of game?
I haven't tried it, but it should be theoretically possible.
You'll need to run the nightlies with custom paths (as you already do for "data", but you will also need the "user" and the "config" parameters to specify those paths)
Or, do it as Starving Poet suggested, that saves you the work with specifying parameters each time.
PS: looking at the original error message, the game crashes because you are using the nightly executable and 1.0 fonts