The percentages and certificate course don't work properly

Hello,
After update I have a few bugs:
1.- The percentages don't work properly. And probably affects the certificate because now the site show me a error message "Fatal error: Cannot redeclare class TCPDF"
2.- Next to the information course information a grey box appears and I can't delete

I tried everything that I now but I don't know where is the problem

could do you support me?

thanks