all text disappear after upgrade

Hi there good morning.
I was using version 2.6 for a long while and this morning i updated it to 2.8. After upgrading it was fine at first but after upgrading the Visual Composer and the boldial asset plugin all the text in my post/page/portfolio is gone. In the editing page they are still there but just could now appear on preview and after posting. I appreciate your help very much. Thank you!