SQL Navigator 7.4 error "Can't initialize OCI. Error -1"

Question

I'm having a problem connecting to an 11g oracle database using Sql Navigator 7.4 running on windows 10 64bit.

I never had any problems but today the error "Can't initialize OCI. Error -1" appeared.

I tried to reinstall SQL navigator and to reinstall the oracle client but nothing changed.

I also tried installing a trial of Toad and with that everything works fine but i need to use SQL Navigator.

Thanks in advance for the help.