The most recent update has stopped you being able to put tech/tech upgrades in any slot on vehicles a dedicated tech slot, so you no longer have the ability to choose to upgrade your vehicles at the cost of cargo space and must instead use a very large amount of in game currancy to increase your tech slots. Any tech upgrades in place before the update that exceeded the number of tech slots after the update were removed from the vehicle and placed, uninstallable, in the vehicle inventory. GOG allows rolling back to a previous game version, which I have done, but the update also added regular autosaves so any save file played after the update but before rolling back to the previous version is unplayable.
