I have been having trouble with this mod (and IFS) endlessly. Tanks couldn't switch, construction port did nothing, etc. Even after I finally got it all to work, it broke when I updated IFS. A fresh install of KSP, loaded with fresh mods didn't even work. Then I noticed that my antivirus had like 15 security alerts. Apparently some antivirus will take out scaleredist.dll and launchpad.dll, so you'll need to exclude them from antivirus if that is your issue. It was driving me crazy, so I hope this helps anyone else with mysterious problems.