why raise this error? Loss cannot go down

[guanyonglai]

[INFO] [2/600] 209/209 11.232529640197754
[INFO] [3/600] 209/209 11.088836669921875
[INFO] [4/600] 209/209 11.040984153747559
[INFO] [5/600] 209/209 10.994289398193362
[INFO] [6/600] 209/209 10.976592063903809
[INFO] [7/600] 209/209 10.965285301208496
[INFO] [8/600] 209/209 10.959023475646973
[INFO] [9/600] 209/209 10.953962326049805
[INFO] [10/600] 209/209 10.952784538269043
[INFO] [11/600] 209/209 10.950810432434082
[INFO] [12/600] 209/209 10.948034286499023
[INFO] [13/600] 209/209 10.950325012207031
[INFO] [14/600] 209/209 10.948730468756755
[INFO] [15/600] 209/209 10.946666717529297