Why can't my VPN config start on vodka?

Check if you have these lines and remove them

reneg-sec 0
block-outside-dns
ncp-ciphers
setenv opt block-outside-dns
register-dns
ignore-unknown-option
data-ciphers
pull
tls-groups

If there is a line tls-version-min, then it should look like this

tls-version-min 1.0

Add an empty line at the end of the config.

If it doesn’t help, then remove the lines at the top anyway and add these lines anywhere

tun-mtu 1390
mssfix 1390