I am trying to train a classifier using haar cascades.The training stops at the first stage.What might be the issue?

Question

create samples.bat

C:\opencv\opencv\build\x64\vc12\bin\opencv_createsamples.exe -info POSITIVES.txt -vec samples1.vec -num 413 -w 50 -h 80 PAUSE

train.bat

C:\opencv\opencv\build\x64\vc12\bin\opencv_traincascade.exe -data classifier -vec samples1.vec -bg negative.txt -numStages 3 -minHitRate 0.999 -maxFalseAlarmRate .5 -numPos 100 -numNeg 300 -w 50 -h 80 -precalcValBuffSize 256 -precalcdxbuffSize 256

I have read a lot of answers but still can't figure out the problem.I am using around 400 positive and 1000 negative images. Everytime i get the following line: Training dataset cannot be filled.Branch training terminated. Thanks in advance for helping.