try to open a ebook with ADE?

I have a valid Adobe-ID and password. 

I have bought an ebook, which should be readable with ADE.

I try to open the ebook in the cloud

I follow the flow of the ebook supplier suggests.

I mark the ebook I want to red.

ADE aks me for ebook-suppler, ID and password: answer:

answer:

adobe ID/password for ebook supplier do not match

Thank you