WatchGuard: failed to open shared memory for openvpn command

I was having problem connecting to a VPN using WatchGuard Mobile VPN with SSL. Here's my log:

2014-11-17T10:16:27.568 VERSION file is 5.23, client version is 5.23
2014-11-17T10:16:27.851 failed to open shared memory for openvpn command (error: 2), please check the WatchGuard SSLVPN Service
2014-11-17T10:16:27.851 Failed to launched openvpn. retCP=0

I tried various things, and it turns out that I was using version 11.9.1. I uninstalled the client and reinstalled the version located on the firewall, which was 11.7.3 and now everything works.

Along the hair pulling and googling, the typo in the last log line made me laugh a bit.