Thanks for reaching out.
It will be very difficult to recognize the exact reason without investigating it through the WordPress admin dashboard. I would suggest you, please provide login credentials for your site in a secure note to examine it further, including:
– WordPress Site URL & Login URL
– WordPress Admin username/password
To create a secure note, click the key icon underneath any of your posts.
Hello, I just added the credentials in the secure note.
The error is still happening whether I’m adding any row or column.
I went to the same Page and same Section but didn’t find the problem you describe here. If you are still facing the problem, please check on any different computer in a different network. If that does not show any problem, then it might be the problem with your machine only, I suggest you consult with a local developer who can inspect and investigate the issue specifically at your machine.