Adobe Digital Edition 4.5 wont start. Help?

I have been using a book on my Adobe Digital Edition 4.5 since the end of Oct 2016 and now it will not open. I have tried uninstalling and re-installing and using the run as administrator having read things online but nothing is working. I have also checked through my anti-virus software and that has not detected any issues. I downloaded the 3 edition but my book wont open on that.

Any assistance gratefully received.