There are different pdf versions existing. I myself have never encountered a situation where a pdf could not be read, but it is possible. You might try one of the "pdf version converter" apps to be found in the internet. Or as you have produced the pdf on a linux machine, there might also be differences between "export as pdf" from within LibreCAD and printing through the standard Linux pdf printing procedure.
An advanced pdf viewer app usually can show the used pdf version.
I have run into this before. Try another USB stick. The stick I had read fine on many different computers except one. I used a different stick and had no further problems. I don't know what was different with that one computer.