I\'m using Laravel and Eloquent for two years and today I\'ve decided to install a fresh Laravel 5.3 and try something with it.
I used an old database schema of mine
You are trying to insert an object, with no 'URL' attribute, into a table that has a 'URL' column without a default value. So the database can't know what to do with that column.
You can do one of three things.
Post your migration or schema, if you need further help.