I was trying to restore my sharepoint application . I have some webparts also be restored. I did the restoration by using sharepoint powershell command "Restore" after those steps when I browse I got an error "Unknown server tag 'WarningWebpart:WarningWebpart'". If anyone could help me, that would be gr8. Thanks
After restoration of Web application, where you browse to?????
If you go to the particular page where you deploy the web part, seems this error. I think the problem is while restoring the web application from one site to another, all lists, libraries, sites, web parts are also restored but it does not get the reference of .wsp file for that web part. So you need to deploy the wsp solution to that restored web application again and check. Hope this helpful....