Weird Documet Fetch Error on Valid Json Document

I have inserted nearly 100 docs in Couchbase using Bulk Operation with gocb . There were no syntax error in json . I have attached a sample json .

The problem is when i try to get the doc by meta id, it failed saying `You must encode a string in a string or interface`

Then I check the doc and binding with golang struct , no problem found and then again if I changed a value just to toggle the edit and save . Lets say a `city` field value changed from 'San Francisco' to 'San Fra' and then save the doc and call from gocb get method . It works fine !

So if I toggle edit and save then the doc fetches fine but other than that it shows the error message above . Also like to mention only the toggled document is fetched fine not the others .

I have tried different couchbase versions but no luck