class-oembed.php is deprecated since version 5.3.0! use wp-includes/class-wp-oembed.php instead. in /home/user/domains/yourdomain. com/public_html/wp-includes/functions.php on line 5051.
The issue may be different in your case, however, I will try to help you check if works, and fix the error, In my case it was featured video plus plugin error.
Solution Quick Fix:
1. Login to your wordpress admin dashboard, and hover over the "Plugins" then click to Plugin etitor
2. From the option Select plugin to edit: box select "Featured video plus plugin, refer the below image.
3. Go to path folder php (i.e EditingEditing featured-video-plus/php/class-oembed.php) open the file name "class-oembed.php"
4. On line Number 19 Replace class-oembed you see in the file with class-wp-oembd that will solve it.
Refer the below Image
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