Upper case


I am trying to change my filenames from lower case to upper case but when i do that it says that file cannot be renamed and file already exists. What am I supposed to do? What is the wrong?

Thank you

[X] Mixed Case on Mac OS Sierra not working : "file already exists"

Thank you for your response. But still doing nothing. I tried. If someone can upload some screenshots how can i do it..

Select the files.
Use the function Convert>Tag-Tag for _FILENAME
Format string: $upper(%_filename%)_

Now use the same function but use
Format string: $replace(%_filename%,_,)

That works!! Thank you very much and excuse but my english are not good enough to explain you!! Thank you again!

For the second step recommended: $trimRight(%_filename%,'_')