What you need.

Obviously the HAFM Submarines mod and all the mods it depends on (CBA and HAFM Navy Core & Weapons part.)

The old HAFM NAVY version for mission makers. ( https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1523395341)

I recomand to make a safty copy of the mission.sqm

What to do.

Before you run the HAFM Submarines Version 2.0 make sure you have no parts of the old version remaining in your addon folder. To achive this uninstall the HAFM Submarines mod and reinstall it.

In some cases it could be nessevery to delete the modfolder manually to do this keep the mod installed launch the Arma 3 launcher navigate to MODS (3rd point from the botton left side) click at the down arrow behind the name of a mod click on the button with the 3 points (if you hover over it it is called display more options) click on open folder in Windows Explorer you will be directed to an folder that can be found in the steam folder under steamapps/common/Arma 3/!Worshop .

Here you have a short cut for every mod you have installed via steam.

Use the short cut for HAFM Submarines and you come to the folder were all HAFM Submarine files should be. Now end the ♥♥♥ of HAFM Submarines in the Worshop and delete everthing in the folder.
After this is done you can reinstall the HAFM Submarines mod via reabo it.

NOTE THIS SHOULD BE DONE ONLY IF THE NORMAL WAY DO NOT WORK.

Back to the normal Way run Arma 3, go to the Editor and try to run the mission you want to bring back in Editor if you get an eror message with something as HAFM_SUB_Men or a message that the sub you used is missing you know that you have a mod missing or a old Version of HAFM_Submarine mod.

If you didn`t get an eror message and Arma only sad there are mods missing for HAFM_Submarines it is the the HAFM_Submarines_Men and HAFM_Submarines_Core you can go to your mission folder and open the mission.sqm with Notepad or another texteditor and search for HAFM and it bring you to a part were all needed addons for this mission are listed now delete "HAFM_Submarines_Men" and "HAFM_Submarines_Core" .

If your editor don`t have a search function scroll to this part:
addons[]=
{
"Addon_example_one" (this is only a space holder for other addons possibly written before the HAFM Addons)

and then delete it.

DO NOT DELETE OTHER HAFM THINGS AS "HAFM_Submarines_Men" AND "HAFM_Submarines_Core" OTHERWISE THE MISSION COULD BE BROKEN AND ISN`T USABLE ANYMORE.

To be 100% save that you can use the mission with the HAFM_Submarines Version 2.0 and depent mods only run Arma 3, open the mission, delete the HAFM stuff in the editor. (use the comment funktion to make notes for what the HAFM stuff was)

Now disale the The old HAFM NAVY version for mission makers in Arma 3 Launcher and run it again, go to the editor and use the HAFM stuff you want use.