Thanks for reaching out.
There have been some other users that reported the same error in the past on this forum. Can you please read all the information on the below thread including the Github report and see if it helps you find a solution?
Thanks for your reply. I have tried the solution on Github connection many times. Still, the error is not resolved.
wc_facebook_external_business_id field to a random 13 character string and press Save
The problem persists…
Sorry to hear that the workaround mentioned in Github was not helpful.
The Github issue is still open and has been marked as a high priority bug, so bear with us while the Facebook for WooCommerce developers are working to fix it.
You can add your own comments and subscribe to the thread to receive further updates on the bug. This will give the developers a good idea of the size and impact of the issue and hopefully it will be resolved within the next releases of Facebook for WooCommerce.