Openvpn[…]: write UDPv4: No buffer space available (code=55)
I recently ran into this problem. During some periods of time, there were many openvpn[…]: write UDPv4: No buffer space available (code=55) errors in the OpenVPN log. I saw a few other threads about this, and just wanted to post about what my discovery was.
In my case, there were OpenVPN packets being dropped by the pfSense traffic shaper, which was recently implemented for unrelated reasons. Once I reconfigured the shaper, the errors disappeared.