Dear Tajudeen

Track errors in MCNP(X) is not always an easy task. Especially you can't find a solution on google, neither in the manual (or perhaps in the 3rd volume (for developpers)

My advices would be :

- try to contact the MCNP forum

- try to come back to a previous working version of your input code, and add step by step until something goes wrong. With a deep thinking process you will probably find the problem.

Hope it help

Tajudeen - from just the error you posted, the following can be ascertained

1) Fortran runtime error (forrtl)

2) an end of file being read (Unit 38) has been reached before all the necessary data was read in.

3) the problem is encountered with the srctcp file

I have no experience with MCNP, so I cannot tell you what the failure means. As Ludovic mentions, you should contact the MCNP developers/forum