Deploying custom webpart to sharepoint 2010 -

in sharepoint 2007 deploy custom webpart have added of application references safe control, got webpart correctly. using sharepoint 2010 , need deploy custom webpart in it, hence followed steps such

1.created webpart(deploy farm solution) using vs2010 of type sharepoint->2010.

2.used sharepoint 2010 management shell add webpart sharepoint site.

3.then using sharepoint central administrator v4->system settings->manage farm solution->mycustomwebpart

4.clicking on webpart , select deploy option, , hence been deployed site.

1. then in sharepoint home site ->site actions-> site settings->site collection features-> select mycustomwebpart , click on activate button.

6.now, show webpart, gone site ->site action-> edit page ,then click on add webpart select custom option , select mycustomwebpart , click on add button.

7.now getting error "file not found" error message web parts maintenance page: if have permission, can use page temporarily close web parts or remove personal settings. more information, contact site administrator.

8.please guide me overcome error. lots of in advance..........