Did you place the OpenCat folder in the Arduino folder and removed the -mail so the folder is just named "OpenCat." This is normally what causes that type of error since the path isn't right to find the file.
I have dowloaded via Github the OpenCat-main.zip file. After that renamed the file to: OpenCar.zip. Then in the Arduino program this file added but then : Specified folder /zip file does not contain a valid library.
Did you place the OpenCat folder in the Arduino folder and removed the -mail so the folder is just named "OpenCat." This is normally what causes that type of error since the path isn't right to find the file.
Rename the folder as OpenCat AFTER unzip.
removed the -main