Hi Mr Rob & Dr Amine,
I used in built compiler option, it proceed further but on loading it gives error below:
In the conventional way while interpreting, I want to add it gives error in line 187 etc... then after few seconds turns in to error in line 15. This type of error I didn't get in the previous versions. Please see the below attachment. My udf consists hardly 100 lines. First it says error in 187 then error in line 15.

Lastly, I tried a simple UDF it interpreted what it is given in manual. It progresses but on running the simulation window of fluent shutsdown.
Seeking your advice in this matter.
Regards Abbas Raza