I wish to do Client Side Validation for document library forms. I have tried doing it using jquery for List forms and it is working fine. But when i tried this for Document Library forms, it's not working. Will it not work for document libraries? Any suggestions would be appreciable.
Are you using the "New Experience" Document Library UI?
If so, then it won't accept any branding, or custom script. Microsoft has disabled everything.
The current answer from Microsoft is: Switch back to Classic Mode