After importing Pages databases from one installation to another, I kept running into this error when trying to create records in the imported databases:

After investigation, I found it is caused by having database relationship fields which point to non-existing tables on the new website. After having all the databases present and re-assigning the fields, the error disappears. 

I am not sure what a good solution would be, but there is probably a better one than just this error. 

I guess we can ignore the error, or do pre-import checks.