Impress not opening .odp files, neither .pptx

Our school uses impress in smartboards for presentations. For about half-a-year it didn’t give any problems but recently, impress started to not open our files. We students prepare our files in win-10 powerpoint. At first I thought it was because the files were .pptx but when I tried to open the same .pptx doc as .odp it again, didn’t open it.

Interesting thing is that when I try to open both .pptx and .odp documents, libreoffice just opened them. So my question is: Why school’s smartboards doesn’t open .pptx and .odp files? And what can we do about it? (Smartboards are using win-10/64 bit)

Sorry for my bad English btw. It’s not my native language.

from the file explorer ?
or/also from within a running Impress ? (menu File > Open …)