If your action has an FsmVar and you add/remove/edit another variable (with no relation to the FsmVar) it causes the FsmVar values to reset. This is a HUGE problem if you need to fix a bug or add another variable that has nothing to do with the FsmVar as it causes the FsmVar to completely lose its values (resets to Float: None). Example as follows.
FROM:
[RequiredField, UIHint(UIHint.Variable)]
public FsmVar variable;
[RequiredField]
public FsmString path;
TO:
[RequiredField, UIHint(UIHint.Variable)]
public FsmVar variable;
[RequiredField]
public FsmString path;
public FsmBool encrypt;
Adding the "encrypt" variable that has nothing to do with "variable", which is an FsmVar still causes any usages of the action to lose its values for "variable". This causes a nightmare of issues as you have to scan through all your FSMs, find the usages, and manually fix them.