Certificate error in Openvpn (was previously working)

Hi,
I recently formatted jffs and enabled scripts, and since then my previously working openvpn connection now fails to connect with the following:

VERIFY ERROR: depth=1, error=self signed certificate in certificate chain: C=TW, ST=TW, L=Taipei, O=ASUS, CN=RT-N66U, emailAddress=me@myhost.mydomain

any known reason for this (I remember in the past there were some warning in FW updates meddling with jffs)?