when opening a file the screen remains transparent and does not display the file
When I attempt to open a spreadsheet or presentation the area remains transparent and all I see is my desktop. I have updated LibreOffice to current version and it still occurs. I am using Pearllinux and have not had this issue before.
Let me make a guess: Your Pearllinux is based on Ubuntu 20.04?
18.04 LTR base
Can you give more details about your desktop environment please: LO full release number & built, Pearl-Linux release, desktop used, graphics card, graphics driver. I don't know much about Pearl Linux, but usually, these are required details for any problem analysis. So they might help someone else to better answer your question.
It might be worth resetting your user profile back to factory. Help | Restart in safe mode. When it restarts a window should open with some options, click the radio button near the bottom that says something like Reset User Profile, then click the button that says restart. You'll lose your settings and you'll have to re-enter your details. Al