USB Port Not Found?

Please explain in detail what you mean in this case with
"downgrading the library."

you seem to use the word "library" in a different than the common way.
libraries in the common way have absolutely nothing to do with the uploading process.

This error-message is too short to analyse the real cause of the problem.
Please adjust the arduino IDE to full verbose output when compiling and uploading
Follow this tutorial to do these adjustments

best regards Stefan