The same thing was reported in another popular map, Lordaeron The Aftermath.
I'll copy a report from another player
"Playing the game now, as gray selecting a single Dalaran Exile will crash gray(tested in single player) but selecting them with other units and selecting more than one doesn't cause the crash"
and
" Troll Shadow Priest has same problem as Dalaran Exile
Barren Last Tuesday at 1:18 AM
Also Troll Ice Priest
Malis Last Tuesday at 12:20 PM
it appears that, in wc3 1.30.1.10211, at least in 1.53f, the fel elves priest unit seems to cause a crash when selected. i realize now that's an old version of the map, though it is still the version of the map in the "link to latest version" post
Malis Last Tuesday at 12:44 PM
just tested with 1.54e, appears to still be true
(apparently as with Dalaran Exile and troll casters)
the problem persists even as far back as 1.51
and as with dalaran exile, only a problem if only 1 of them is selected
Barren Last Tuesday at 8:00 PM
Also Dalaran Constructionist (for purple, I think that's it) has the problem as well
"
All of these happened since the 1.30 chaotic patches and even now in the current live patch!

This problem never existed before.
Selecting certain units - crash. No idea why... maybe their sound pack that activates when u click them triggers a crash?
But another player said that the problem is in the unit training tool tip..
"
Richardik Last Sunday at 3:17 PM
^thats a problem with tech tree names of "novice, adept, master"
" Idkk but please fix it. :c