First, seeing the standard main menu does not necessarily mean the mod isn't working. There are various mods that do not customize the main menu... there are mods which do not customize the GUI at all. Did you try to actually play a map, to see if some of the rule changes brought by the mod are in place?
In case the mod really isn't working...
If you cannot later play "locally" a certain mod that you autodownloaded by playing it on a server, it may be because your local copy may not be "complete" (as autodownload only gets the pk3 files required at that point), e.g. your machine may have downloaded the client-side GUI changes only, but not the server part gamecode, if they were stored in different pk3 files on the server... or maybe the mod may search for a specific series of additional maps (there are a few mods with such requirements), and you don't own some of them.
Maybe you may try to find an installation package for that mod on the web, or may take a look to the server infos (e.g. from
dpmaster website) too see if there is a visible value for
sv_dlURL variable ("
DO NOT LINK[/b]) h t t p s : / / openarena . wikia . com/wiki/Fast_downloading]fast downloading"), then go to such path with a web browser to try if you can manually download additional files from there.
See also: (
DO NOT LINK) h t t p s : / / openarena . wikia . com/wiki/Manual/Using_Mods