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