This happened twice to me today on two different games. The person in question (was actually a bot one of the times) was completely invisible to me for the duration of the game. The bot was on the opposite team & it was very hard to kill. The player was on my team & it was on two different maps also.

Here is a screenie of it. The guy is actually very close in front of me. He's just buffed my health so is obviously not too far away.

Also got a graphical bug on the weapon buff info top left. that happens a lot.

http://imageshack.us/f/268/2011051800005.jpg/

Yea, this is a fun one...

What I do in this situation is hang back and buff the hell out of my team, in my experience, the next round should resolve the issue.

As I've not seen the problem in a few days, you could try resetting some of the video bits if it occurs again [ Might cause a crash to the desktop if you reload the main engine or something, but in the name of debugging, it's worth it ]

reloadAnims reloads animations
reloadDecls reloads declarations
reloadEngine reloads the engine down, including the file system
reloadGuiGlobals reloads gloabal gui properties
reloadImages reloads images
reloadLanguage reload language dictionaries
reloadModels reloads models
reloadScript reloads scripts
reloadSoundEffects reloads all sound effects
reloadSounds reloads all sounds
reloadSurface reloads the decl and images for selected surface
reloadUserGroups reloads user groups
reloadVirtualMaterials reloads virtual materials

Not sure if any of these will work, just had them written down for troubleshooting another issue.

GL!

Had this the other night in a 16 player game. All but two ther players on my team were invisible. Just the three of us running around getting our arses handed to us over and over until we just had to leave.

It was hilarious for about the first 40 seconds. It got a bit stale quickly after that.