problem with epoch length

[ShagReza]

hi,

I just can run the program with epoch_len=2 and as I increase it to even just 5, it stops with the following error. Therefore, I can not train the model on the entire database in each epoch.

Error:

tensorflow/core/framework/op_kernel.cc:1767] OP_REQUIRES failed at ctc_loss_op.cc:206 : Invalid argument: Saw a non-null label (index >= num_classes - 1) following a null label, batch: 0 num_classes: 29 labels: 26,9,16,0,28,5,0,3,15,4,0 labels seen so far: 26,9,16,0

Thanks in advance