# reaply :
I did say that a server we played on worked.
The server is probably running a full version of ARMA II, and if there aren't any required mods, you can most likely still join it using ARMA II Free.
If that's the case, the server is probably having no issue processing the scripts and such, but when you host/play with A2F, you'll run into issues.
You might have better luck posting in the thread for the Dynamic Zombie Sandbox
and asking about compatibility with the free version.
Just a side note: make sure when you download the mission you're grabbing the correct version. For Arma2Free, you should be using the A2 version on the download page.