Am 21.05.2018 um 01:34 schrieb Allin Cottrell:
 This should now be fixed in git and snapshots. At least, my English + 
 Greek "mixed language" filename is now opened in gretl OK on 
 double-click. So I guess your case should be fine too. I don't know 
 about Periklis' case since there was clearly something additional 
 wrong there. 
Allin, I think the latest snapshot has some unintended fallout: On my 
German system and with the language setting set to "Automatic" as usual, 
gretl now starts up in English.
cheers,
sven