Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration. You can use the Add-Migration command to write the pending model changes to a code-based migration.
This error occurs when you have pending changes in your database migrations that have not been added yet. If you find this error staring you in the face during your programming adventures, simply type
Add-Migration. This will take all of the database updates you have made (inadvertently or explicitly) since the last migration and add them to a new database migration file.
Once your pending changes are all synced up,
Update-Database will work again.