First, can you post a link to your site?
Honestly, you can’t expect me to manually copy every single file in every single subfolder.
No, you do the wp-admin directory and wp-includes directory. Upload the individual files from the new wp-content folder to your existing wp-content folder, overwriting existing files. Do NOT delete your existing wp-content folder. Do NOT delete any files or folders in your existing wp-content directory (except for the one being overwritten by new files). I think there are 14 of those and that can be done all at one time by ftp.
I’m not sure what this means?
https://codex.www.ads-software.com/Using_Your_Browser_to_Diagnose_JavaScript_Errors
If you read and follow the trouble shooting link there are other things you should try. Try them all if necessary.
you guys need to find which exact file is the problem and let us know so we can just reupload the offending file.
There is no offending file. By this time thousands of users have installed 3.5 without problems. Please go thru the trouble shooting guide.