Window on Adobe Digital Editions does not open - stays black - Program Crashes

I am trying - as always - to continue reading, but alas the program seems to have stopped working altogether. 

I have version 4.5. 12 I think, i.e. the last one published.

Temporarily a black box opens on the top left of the screen, that is the only reaction I get. From the task bar the program is shown to be active,  in the Task manager it is said to occupy 127 MB of RAM, however there is no reaction anywhere. Alt Tab to jump to the process does not work, I have repeatedly tried this.

If I click on the taskbar it gives the usual options of waiting for process or ending process.

I am more and more getting frustrated and would have long gone to a different product if it was not where I had academic 70 books inside, all paid for with about 2500 EUR stuck behind the ADE DRM system. 

Are there any work arounds?