Cannot authorize a computer because AdobeID "not correct?"

I bought a book and am trying to get it on my ereader. I have an old Sony reader PRS-T2.

The book is secured but for some reason I cannot get it on my ereader. Adobe Digital Editions cannot find my e reader? My pc does find it, but I cannot just copy the file to my reader because it is an .acsm file (secured).

Also, I can also not autorize my pc because it says my AdobeID isn't correct, even though I just created it half an hour ago and I am sure it is correct. Also, in my browser on the adobe website I can login with these credentials.

What to do?