I am trying to input another CAESAR II file in my existing CAESAR II file.
The other CAESAR II file is created by saving as existing file so version issue is ruled out.
Also I tried unit conversion option for both files as suggested by some in Caesar forum but not helping.

Can I know what the problem could be?

Try to close then re-start your CAESAR II. If problem still persist, I recommend to reinstall a new version of software with new service pack.

Could you be more specific with the problem? Is CAESAR not adding your 2 calculations in one? Do you recieve any message?

Remember units must be the same when merging files.

Regards.