Here are the bugs that plan to be fixed in this hotfix.
Attack – Autofill – When setting up the attack defense units are added to the waves when using autofill
World Map – Movements – Support – All open dialogs close when a support movement arrives or starts
Attack – Autofill – When setting up the attack shields are added even if there are only melee defenders when using autofill
Autofill – Tool slots are overfilled when you set up tools before using autofill
Research – Ambulance Coach – Units per slot not increasing despite having researched “ambulance coach”
Here is the official HotFix post on the forums.