Hello!
I generated in Ubuntu, the CA, DH, crt ans .key via easy-rsa exported them and imported them into the my RUT, but i cannot save the config of the OpeVPN server, because something seems incompatiple - how could i check what of the certifcates etc. are not correct and why?
I recommend upgrading your device to the latest firmware version 7.09.4 without selecting “Keep settings” for testing purposes. Please try this, configure OpenVPN on the fresh device, and let me know if the error persists.