Created attachment 119184 [details]
What I see
I made some fomulas on a writer page with libreOffice 5.0.2, When I opened it with 18.104.22.168, all the characters seemed to be written in wingdins (and it's not the case) !
Created attachment 119185 [details]
the file which causes me trouble
Nothing wrong with that file. The machine with 22.214.171.124 is simply missing the OpenSymbol file (due to a mysterious bug in the installer, see Bug 76239).
*** This bug has been marked as a duplicate of bug 76239 ***
(In reply to Maxim Monastirsky from comment #2)
> OpenSymbol file
I meant OpenSymbol font.