NameError: name 'LineCollection' is not defined

[S1J2]

Hello, recently I started to get following error everytime Im trying to simulate:

..\signalintegrity-1.3.2\SignalIntegrity\App\SParameterViewerWindow.py", line 1006, in PlotSParameter
lc = LineCollection(segments, linewidths=slw,color='blue')
NameError: name 'LineCollection' is not defined

I noticed that if I copy line 60 "from matplotlib.collections import LineCollection" in front of line 45 ( class Sparameterdialog..) issue disapear and I can proceed with simulations.
Opening this same script in Spyder displays some warning at these lines. Im not much into python and OO programming so I wasnt investigate further. Is it some known issue with known solution or could it be by some mismatch in dependecies?

[PetePupalaikis]

I have never seen this problem, but looking at the code, I can see that this could be a problem. I moved a lot of imports into the functions where they are used, but I can see that what I did here could cause this problem. Your fix is 100% correct and in fact, should be placed in a few more locations. I will fix this for next release.

[PetePupalaikis]

Ah - now I can repeat the problem, and it's really bad. Sorry about that. It comes about when you set 'variable line width' in your s-parameter view. And once the problem occurs, you can never get back to change it. It's a very bad bug. Thanks for telling me.