PayPal Account not Accepted

if @Abambo's first link doesn't help,  change what you need to make your purchase (in part, change the country associated with your id), before contacting support:

The country associated with your adobe id must match the store you purchase from and must match the payment address. otherwise, change what's necessary:

change country associated with adobe id - https://helpx.adobe.com/x-productkb/policy-pricing/change-country-associated-with-adobe-id.html

change credit card and/or billing address, https://helpx.adobe.com/manage-account/using/update-billing-information.html

change currency - https://forums.adobe.com/thread/1999694

change store - http://www.adobe.com/store_selector/storeselector.html

change adobe.com website language - https://forums.adobe.com/thread/1999693

 Deinstall all Adobe and Install it again from the German Site? 

By @Maximilian26463434w0rd

That won't help you to change the invoice country. You should be able to change your country by updating your payment information. See here: https://helpx.adobe.com/lu_en/x-productkb/policy-pricing/change-country-associated-with-adobe-id.html

If that does not help, I suggest you contact Adobe customer care. Adobe customer care can be contacted by beginning a secure chat session at https://helpx.adobe.com/contact.html?rghtup=autoOpen. Pop-up blockers need to be disabled! If the chat window fails to open, or is non-responsive, use a different device to start the interaction.
Support phone numbers may be found here: https://helpx.adobe.com/contact/phone.html. Please note that phone charges may apply.

(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
https://community.adobe.com/t5/account-payment-plan/how-to-contact-adobe-support/td-p/11843852)