Here you will find all the current errata topics sorted by chapter number of the rulebook:
9.11.4 Loading Immobile Artillery
In order to load immobile artillery, the transporting unit moves into its hex. The immobile artillery unit must not have any of the following status markers: delayed action, suppressed, fall back, or close combat. Since they cannot be loaded onto the transport with those status markers, the transport is not allowed to enter the hex itself, (as stacking limits would apply).
Once the transport enters the hex the immobile artillery is considered loaded. This ends the activation for the transport, which is marked with a delayed action.
9.11.5 Unloading Immobile Artillery
Unloading immobile artillery is done during its transport’s activation. It must be unloaded into a hex adjacent to its transport. The immobile artillery unit is marked with a delayed action.
During the unloading, the players should make sure they apply the stacking limit of one friendly unit per hex.
They cannot unload into a hex containing an enemy unit. Immobile artillery also cannot unload if their transport has moved into harsh terrain that turn.
Unloading can attract reaction fire
The aim of the rule is to give players the option to move their immobile artillery after they deploy it, but make it very difficult to do so.