Non Linux Devices properly connect to Guest_WLAN but Linux won't...

Question

WLan in general works properly... 
 Guest WLan works properly for Windows Laptops, MacOS and a variety of Mobiles... 
 But Linux won't connect... 
 UTM 9.604-2 --> RED 15 --> AP 15 
 ...anybody else facing this general problem...??? 
 Cheers, 
 UN...

SaschaParis · Answer

Hi UN 
 A unscientific guess... 
 I personally also use some linux devices which usually runs on older Laptops. Probably you have there older AGN wireless cards as Intel 4965 or similar built in. If yes - you probably also might have enabled fast transition on the AP's, which won't work with those old WIFI cards (also don't if running Windows on those devices btw.) 
 If fast transistion is enabled on your AP's, give it a shot with that feature disabled. 
 /Sascha