Well I thought this problem was present because master server list for infiltration is down?
I dont know why did you change thet but anyway here is the problem.Change thet and it will work.
your infiltration.ini
[INF_Browser_All_UT]
ListFactories[0]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=infmaster.sobservers.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[1]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=infmaster2.sobservers.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[2]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=unreal.epicgames.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[3]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=master0.gamespy.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[4]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=master.mplayer.com,MasterServerTCPPort=28900,Region=0,GameName=ut
bHidden=True
bFallbackFactories=True
ServerListTitle=
URLAppend=
AutoRefreshTime=0
bNoAutoSort=False
ListFactories[5]=
ListFactories[6]=
ListFactories[7]=
ListFactories[8]=
ListFactories[9]=
[INF_Browser_ALL_INF]
ListFactories[0]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilTeamGamePlus,bCompatibleServersOnly=True
ListFactories[1]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilDeathMatchPlus,bCompatibleServersOnly=True
ListFactories[2]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilAssault,bCompatibleServersOnly=True
ListFactories[3]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilCTFGame,bCompatibleServersOnly=True
ListFactories[4]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilDomination,bCompatibleServersOnly=True
ListFactories[5]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilLastManStanding,bCompatibleServersOnly=True
ListFactories[6]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=INFg_Specialist,bCompatibleServersOnly=True
ListFactories[7]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=INFg_EASGame,bCompatibleServersOnly=True
ListFactories[8]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameStyle=Infiltration,bCompatibleServersOnly=True
ListFactories[9]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,bNoStandardGameTypes=True,bCompatibleServersOnly=True
delete and copy this to fix the problem
[INF_Browser_All_UT]
ListFactories[0]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=infmaster.sobservers.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[1]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=infmaster2.sobservers.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[2]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=unreal.epicgames.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[3]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=master0.gamespy.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[4]=INF_Browser.INF_BrowserGSpyFact,MasterServerAddress=master.mplayer.com,MasterServerTCPPort=28900,Region=0,GameName=ut
bHidden=True
bFallbackFactories=True
ServerListTitle=
URLAppend=
AutoRefreshTime=0
bNoAutoSort=False
ListFactories[5]=
ListFactories[6]=
ListFactories[7]=
ListFactories[8]=
ListFactories[9]=
[INF_Browser_ALL_INF]
ListFactories[0]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilTeamGamePlus,bCompatibleServersOnly=True
ListFactories[1]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilDeathMatchPlus,bCompatibleServersOnly=True
ListFactories[2]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilAssault,bCompatibleServersOnly=True
ListFactories[3]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilCTFGame,bCompatibleServersOnly=True
ListFactories[4]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilDomination,bCompatibleServersOnly=True
ListFactories[5]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=InfilLastManStanding,bCompatibleServersOnly=True
ListFactories[6]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=INFg_Specialist,bCompatibleServersOnly=True
ListFactories[7]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameType=INFg_EASGame,bCompatibleServersOnly=True
ListFactories[8]=INF_Browser.INF_BrowserSubsetFact,SupersetTag=INF_Browser_All_UT,GameStyle=Infiltration,bCompatibleServersOnly=True