How to upload files with using two different users

I have a scenario where I have to upload a file using two different users. So i created one Keywords, and i gave the path of two files, and i call this Keywords in my test case.
what happens is:

1-first test
Action : The first user logs in, fills in all possible fields then clicks on attach file
Excepted result : file is upload successfully
Actual result : file is uploaded successfully
and then he logs out.

2- second test
Action : another user logs in, does the same scenario and then clicks on attach file.
Excepted result : file is uploaded successfully
Actual result : the system displayed the file manager window without attahc the file.

Anyone can suggest solution?

thank you

It sounds to me like the File Manager is waiting for the filename (with full pathway) to be supplied to it. Are you using two different filenames? Do you have them “hardcoded” or are you getting the reference(s) from somewhere?