How to fix the “error 2025: XML Schema validation failed for mapping schema.” error

The Problem

You’ve been upgrading and downgrading Entity Framework, and just when everything seems to be working, you get an error of

Schema specified is not valid. Errors:
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared..
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared..
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared..
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared..
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared..
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared..
<File Unknown>(0,0) : error 2025: XML Schema validation failed for mapping schema. Schema Error Information : The ‘http://schemas.microsoft.com/ado/2012/10/edm/migrations:IsSystem’ attribute is not declared.

The Cause

The data migrations have gotten out of sync

The Solution

The solution (use at your own risk)

1. Delete the migrations folder and
2. Drop the _MigrationHistory table in the database
3. Run Enable-migrations -Force in the package manager console
4. Add a migration
5. Check the migration file that is created – it should have a listing of your entire database – delete the table creation and dropping code
6. run update-database -verbose

You should be back in business!

 

Written By Steve French

 

This entry was posted on Tuesday, June 4th, 2013 at 2:01 pmand is filed under Entity Framework . You can follow any comments to this entry through the RSS 2.0 feed. You can leave a comment, or trackback from your own site.

 

 

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