Diagnosing and making recommendations regarding production systems and outages is really not what this forum is for. These issues need detailed technical diagnosis and then recommendations can be made accordingly. Please log an SR with Oracle Support so that we can assist you.
Superficially it looks like you ran out of space in 'Temp' so increasing TempSize value (requires database to be unloaded from memory and re-loaded to take effect) *might* solve the problem. But ideally proper diagnosis via an SR is the best plan here.