Trouble 3: If you have permission, you can use this page to temporarily close Web Parts or remove personal settings. For more information, contact your site administrator

Step 1: After add web part, you click button Export …

Step 2: Appear error below

Step 3: Because permission of system, you can edit “trust level” in file web.config with path to port contain your web application (Ex: C:\inetpub\wwwroot\wss\VirtualDirectories\80)

Step 4: Find “trust level” and change “WSS_Minimal” to “Full” and save file.