When publishing a mission to the Steam Workshop, if you add the "&" ampersand symbol to the mission description, it will bug the description when viewing in the Arma 3 mission selection screen.

For example, i name my mission "Tank Hunters - SP & 7 player coop" and upload it.

When viewing the mission in game, the description will stop after "Tank Hunters - SP ?". A question mark is placed where the error occurs. Once removing the ampersand symbol fixed the issue for all my workshop items.

Note: In steam, the “&” symbol works fine. Also when creating the workshop item, the title of the mission can have the "&" symbol without issues (See Screenshots). {F22814}