One of my client was unable to modify the maintenance plan using SSMS. When we did various tests, we found that existing maintenance plans could execute and work. We tried creating a new maintenance plan and found it to be working. So, our issue is confined to “unable to modify existing plans”. Here is the error message
Error: Microsoft SQL Server Management Studio is unable to load this document:
Could not load type ‘Microsoft.SQLServer.Dts.Runtime.Wrapper.IDTSPackageSigning100’ from assembly
The error was talking about version 10.0.0.0 and I think it’s the same for SQL 2008 and SQL 2008 R2.
SSMS issue was resolved for my client by installing the right version of shared components. There were 2 instances on this machine; SQL Server 2008 RTM and SQL Server 2008 R2. We uninstalled shared components for the SQL Server RTM and installed shared components from SQL Server 2008 R2 media. After doing the above steps, we could edit the maintenance plans.
Here are a few related blog posts about SQL Server Maitainance Plans:
Reference:Pinal Dave (http://blog.SQLAuthority.com)