Same error here.
A bunch of:
2021-04-03 15:55:59,590 DEBG 'start-script' stderr output:
[#] ip link add wg0 type wireguard
2021-04-03 15:55:59,592 DEBG 'start-script' stderr output:
[#] wg setconf wg0 /dev/fd/63
2021-04-03 15:55:59,592 DEBG 'start-script' stderr output:
Line unrecognized: `PublicKey='
Configuration parsing error
2021-04-03 15:55:59,594 DEBG 'start-script' stderr output:
[#] ip link delete dev wg0
2021-04-03 15:55:59,629 DEBG 'start-script' stdout output:
[warn] WireGuard interface failed to come 'up', exit code is '1'
Was working till some hour ago...