You’ve developed your visual web part and deployed it to your SharePoint Server. When you add that web part to the page, if you get the error states that “Type is not registered as safe”, you have to check a few things in your visual web part project.
Check your .webpart file. Type field must contain the strong name of the assembly.
Next thing to check is safe control entries. If you renamed or refactored your web part, the safe control entry remains same So you might probably forget to change these entries.
If the safe control entry is not correct, you can easily remove the existing safe control entry and add a new one.
Hope this helps…