Welcome to Shopify Community. My name is Olivia and I work here.
Thank you for reaching out to our network and sharing your question with us. Are you using the Google Channel App developed by Shopify? If so, I can certainly assist you with further troubleshooting.
Google requires you to have a unique product identifier for each of your products. These identifiers let Google match your product with similar products on Google Shopping. If these identifiers aren't correct, then Google doesn't publish your products and your account could be suspended. Learn more about unique product identifiers from Google Merchant Center Help.
To determine the correct resolution, can you please confirm if you have marked these items as custom products in Google Fields?
I look forward to your reply,
I have just posted this on a similar problem, so I hope it helps......(it should work if you sell 'custom products' and do NOT have barcodes / GTIN numbers)
I have literally spent all day going around in circles, from 'link to link' to work this out and I wanted to help people save time and unnecessary stress!
First of all.....STOP searching in Shopify and head over to your Google merchant centre account, go to the left hand menu and click 'feeds'.
If you sell custom products and don't have a clue about 'feeds', gtin's / mpn's etc. then here's how to get rid of the 'missing identifiers' error you're probably seeing at the bottom of your product diagnostics page.
(this is for anyone who has linked their store to Google from Shopify, (added as a sales channel), which automatically uploads all your products using 'content API').....I'm not sure if you will have the same options if you've uploaded your products one by one, sorry!
1. Click on the content API link under 'feed name'
2. There you will find the elusive 'feed rules' menu....click!
3. Click the blue + button to create new feed rule
4. Choose processed attributes
5. Scroll down to choose 'identifier exists' and set to 'no'
6. Then click 'save as draft' and click test, (or apply if test doesn't work) *
* For me, the 'test' didn't work, so after waiting approx 10 mins, I tried again, still didn't work....so after another few mins, I clicked 'apply', waited 10 mins, went to back to feeds - content API - feed rules - and your new attribute rule should be there, set to no!
To check it worked properly, go back to your product diagnostics in the left hand menu....and voila! your error message should be gone
I really hope this helped.....as it has driven me crazy for the last couple of months, but today was the day to sort it out!!!!
(I think the last 2 steps in the screenshots might be the wrong way around, but I ran out of brain cells by the time I realised, hope it still makes sense)
Thank you for your reply, @carsss11.
Please let us know,