UCF-101 test loop getting stuck -- Script is running but video is stuck

[ngun7]

On running CUDA_VISIBLE_DEVICES=0 python finetune.py ucf101 flow 2 , the video got stuck in the process. I tried with test lists 1, 2, 3 but it's getting stuck at the different videos. It is working fine with the only optical flow but when ran only RGB or mixed loop just get stuck after some time. I suspect there is something with RGB code.
FYI: I tried with 2 different sets of RGB frames and the RBG list is valid enough.