Libreoffice throws error instead of opening

I had used Libreoffice on Windows. I was so excited to finally make the plunge to Ubuntu xfce 18.04 but Libreoffice isn’t starting there. I get the message in the terminal ‘ERROR: /proc not mounted. Libreoffice is unlikely to work well if at all.’ How do I fix this? Firefox and all the other Linux apps I need have been working without complaint.

Why do you use tags android and smartphone? The question seems to have nothing to do with android. Please retag. Or are you just leaving off the important information that you are running Ubuntu inside an android or in some chroot environment?