Note : This appears only on Linux latest version (1.82.144710)
After version CUP 1.11 most of the units and weapons placed in the eden editor display this message :
"cannot open object a3\data_f\proxies\weapon_slots\magazineslot.p3d "
It is (IMHO) due to a case sensitive naming of MAGAZINESLOT.p3d which appears in all-caps in bohemia's "data_f" as shown here :
And may be named in small-case in your addons. Linux is case sensitive, so the Arma Tux version cannot find those models.
Or .... It may be somthing else ?