In my local machine i deployed my web part and also i can use it but when i want to use this web part another sharepoint site importing web part shows this error:
Does anybody have any suggestions?
Not much info to go buy, but if you imported a custom web part to another SharePoint site, it will not work!
The reason is that the assembly behind the web part is not allowed to run on that site by the safe mode parser (SafeControls in web.config).
Try and install the web part solution in the new SharePoint solution and see if this solves the problem!