The issue is caused by an invalid IPFS link.
Steps to FIX the issue:
Update the metadata (including views, etc...)
Copy the generated JSON
Upload the metadata JSON to IPFS
You can use Pinata for this.
Update the metadata link in the code
Replace all occurences of sp.metadata_of_url("https://example.com") with sp.metadata_of_url("<...
The FA1.2 template was updated this week by Keefer Taylor. It will be updated in https://smartpy.io templates this weekend.
Template link: https://smartpy.io/ide?cid=Qma5v9x6xjbzB82hjhr5Y5Sw2oppRzhyNBN11eVVyXpvxv&k=ea98e1d25d85d92f75c7
Here is an example after deployment: https://tzcomet.io/#/explorer%3Fexplorer-input%...