Are you referring to "Facebook Sales" on the left side in Shopify?
Having the same issue but don't have the "Facebook Sales" Section, just Facebook.
Encountering the same issue atm and can't seem to fix it.
I also can't login as a co-worker in business manager. Always get "There was a problem, try it again later."
I am also having this problem. I use Shopify lite to incorporate buttons onto my own site and into my Facebook business page. About half of my products keep having this error no matter what I do. It's deeply annoying and so far none of these solutions that have worked for others seem to be working for me.
Had the same issue but seem to have resolved it...
1) Go to 'All Products' under 'Products' drop down
2) Check box to the left of the thumb nail image of your product
3)Select 'More Actions'
4)Select make products available
5) Save and wait 15 minutes for Shopify to refresh and process... This all worked for me.
Hope that helps