I am unable to reproduce this on 100D.100A and seems to be only affecting 100D.100B (& maybe C versions as well?) however which lens did you try this on with?
I tried to reproduce this in video above with only partly success. Touch screen isn't working at all on my end?
i tested again , this time no error, just a non working lcd
the best part is, this error only shows when i want to do a long exposure picture with the lcd on, i tried this with my 3 lens (Canon EFS 18-55mm STM , Canon EF 50mm , Tamron 70-300 Di) and the results are the same, non working lcd
if my shutter is 10 sec or more and i switch to the liveview mode the screen goes black and only the power on/off mode works, but if i turn off the exposure simulation this problem disappear
tomorow i make a video to show the problem, now i only have 5 hours until work
my ml settings are reseted after the error so i dont know which combination makes that error