Hello,

i found a way to fix it.
You have to open the mission file in a text editor, then go to the mod folder of ArmA 3 and find the file that causes problems (the renamed version of course, since the original doesn't exist anymore).
In the case with "A3_soft_F_Galkin" the name was changed to "soft_f". Now change the name in the missionfile, the new name should be "A3_soft_f".

Its similar to Wolv´s way, only you don´t replace the name with anything, you should get the same file that you had, since it was in use, you are going to need it.