In attempting to Deploy a Workflow Template for Testing, the assembly DLL containing workflow foundation programs associated with a workflow template be installed in the GAC prior to use.
That means that you must add a signing key to your assembly project so that its output assembly DLL is built with a strong name.
It this case, I have adopted the policy of signing with a string value of my last name and the present date.
To assign a strong-name key
1. In Solution Explorer, right-click the bold project name that is in bold type, and then select Properties.
2. Click the Signing tab.
3. Select the Sign the assembly checkbox.
4. From the Choose a strong name key file: combo box, select <New…>
5. In the Create Strong Name Key dialog box, in the Key file name: text field, enter a string value.
6. Clear Protect my key file with a password, and then click OK.
7. Close the Signing window.
8. From the Build menu, click Build Solution.
9. From the File menu, click Save All.