when copy file get error The target file is a directory, not a file

Question

I work on asp.net core 3.1 web api

I get exception error as below :

Exception The target file is a directory, not a file. on file.copy

this lines generated exception

System.IO.File.Copy(OutputfilePath, Path.Combine(exportDirectory, fileName), true);

two files can access and open it when i open on fil explorer but issue

as above

so How to solve this issue please ?

 

what i try  as below :