Could'nt copy and paste within same project

while working on my site, i couldnt copy and paste div blocks within the same project, it is showing the error that couldnt read native clipboard data . I have tried every possible method to resolve this but i am not able to find any solution , and my lot of time has been wasted. Do help me in this. Thankyou!

You would need to post a copy of your site in order for anyone to help you (read only link).