Unable to call user defined function in math script node

[Shrinivas]

Hi,

I am using math script node in my VI. When I call user defined functions(.m files) in the math script node, it is not recognising the user defined functions. (.m file path is correct. )

When I call the same user defined function in blank VI, it was running good for first couple of times. Now it is giving error without any modification on the code.  

Am I doing anything wrong? I am confused and looking for some guidance to solve this problem. 

I am attaching the SubI  for your refernce.

Thank you in advance!