im not sure if anyone hav such problem like this before....
currently i kena this also. =.='''

previously my cydia was working fine. it happens when i tried to add an old source... the cydia seems able to detect it and getting update or something from the source link. but half way it says dont know what error thing. then it quit to main menu.
after that it seems to keep auto quit back to main menu whenever i try to open cydia. i can enter appstore, can enter installer. but i cant enter cydia. keep jumping back to the main menu...

i tried restart my iphone. i tried bosspref fix user dir permissions. both doesnt help.

tried look into forum here, only manage to find someone whom ask about this problem. -__-

anyone got any experience on this can help me pls?

thanks for the guide
but i dont know how to ssh at the moment and i don hav mobile terminal inside my phone.
cant open cydia and cant find it in installer. only got open ssh installed.

so i guess i will just follow the guide to restore and restore it 1st. and thanks again. will do research further more on this mobile terminal after i restore.