I can have two instances of DMD 1.3 but it won't let me open 1.4 and 1.3 together.
I first noticed this while trying to open both so I could make my icons the same in both versions.
This is kind of an issue since I am often needing to have multiple programs open at one time to compare programs or whatever. I realize I can open a 1.3 into 1.4 but what does that do to the 1.3 program? Is it still OK to later open in 1.3? What happens with connecting to a 1.3 processor using 1.4? I ask these questions because I have had issues with DS4 hosing a DS5 program's documentation if the DS5 was using iBoxes. Hosing as in the Rung Comments floating off elsewhere and that happens immediately in DSx, no user intervention required

So yeah, I get the whole "Why aren't you upgrading everything?" concept, but supporting multiple customers and then trying to get
them upgraded (did I mention custom settings don't migrate?

)
Is there any "Fix" for this? Even temporarily disabling comms in 1.3 so it can open would be OK usually.