My M200 was standing few months. Today I tried to start printing and it started with hiting hotend by platform and it was pushing on it!!! Had to turn of printer.
Same with tring to do callibration. Platform is pushing hotend up :((
please, have a look at our troubleshooting manual and follow the steps - this will help you find a root of the problem.
However, as the printer has not been used for several months - I suspect there might be some material remains on the nozzle, hence the electrical circuit in the printer cannot be completed. You can heat the extruder and clean the nozzle with a spatula, as well as gently clean its tip with sandpaper.
Also, does the nozzle hit the calibration square? If not - this could mean the rails are either misaligned or dry - clean them with acetone/IPA and lubricate with silicone oil.