How to solve an error in using the database Relationship Diagram

How to solve an error in using the database Relationship Diagram

In SQL Server 2005, I have encountered the following problems:Errors always occur when using the database relationship diagram. The errors are generally as follows:

 

However, it seems that the problem cannot be solved as prompted,The solution is as follows:

 

1, Select the corresponding database, right-click, and select "properties"

 

2In the displayed database Properties dialog box, select "option" and select "Compatibility Level" from the drop-down list.

"SQL Server 2005 (90)Click OK"

3When you double-click the database relationship diagram under the corresponding database again, the following prompt is displayed:

Ignore it and click "yes". At this time, the problem should be solved!

4,