Error Function #1516 occurs every increment due to ground forces.
Two formations exist as in the picture attached/below. Both were created via the organizations tab, with the 1st being created from the instant org button. Deleting the formations fixes the error. removing the MLRS companies from the formations also fixes the error. but re adding them causes it again. removing all the tank companies also fixes the error, they can be re-added but if there is 4 or more tank companies in one formation, or if there is 3 tank companies and at least one MLRS company, the error persists.
I have noticed from messing around with them that the tank company actually has 0 units of a construction/cap vehicle that i set to zero but forgot to delete, while the MLRS has 1 (intentionally). Im no programmer but i suspect some sort of float error or something with the total formation due to the existence of the 0 units in the tank company, since the error does not occur when the formation consists of only MLRS units. the error does not persist when the tank companies are under no hierarchy.
https://imgur.com/a/zoNuCKy