COBRT021 File is a directory (Fatal)

You have tried to WRITE to a directory instead of to a file.

Alternatively, the attributes are not set up correctly to allow you to access a file. That is, it is marked as read-only or you don't have sufficient rights to open it.

Resolution:

Recode your program so that it writes to a file and not to a directory.

You need to either change your file access attributes or recode your program so that it does not violate the existing attributes.