infinite loop when using subroutine in ABAQUS

I added my subroutine in job/general tab in ABAQUS CAE. When I submit my job, it showed" The file has been submitted for analysis" and never stop, it starts an infinite loop. The job can not be killed, too. I tried some examples from user manual, it is the same problem. Anyone know something about this? The manual examples are .f file and my Windows ABAQUS required .for file. I used Notebook to save .for file. Does this make any difference?

Thanks