I am having this undocking bug as well, and its really getting on my nerves. I am running vens revamp from the master branch, as well as a few other mods. This is KSP 1.1.3 64bit on Windows
I am performing an apollo style mission, and my lander is using the regular size docking port (1.25m) and the main ship is using the regular size port as well, but the one with the integrated parachute. I tried docking and undocking over the Mun, and nothing happened. However I was able to undock in kerbin orbit, which i thought was weird. I saw what blowfish said above that this is caused by time warp mods, and I believe the only mod I have that does that is kerbal alarm clock (which is using the 1.1.3 version)
Here is a spreadsheet with all the mods I am using as well as the versions.
Output Log
I had tried the fix someone else had posted just above me, and It didn't help.
I'd appreciate any help in fixing this and let me know if you need any more information.
Thank you
Having this issue, and I have one question for you. When you said you tried the same vessel again, did you relaunch it, or did you continue where you left off from the tracking station? I tried reloading the same vessel that I had in Mun orbit and it didn't help. I just wish fully reproducing this error wouldn't take so much time