Werner_Gminder, I am sorry but Error 126 indicates the download is damaged. Please try using a different Internet connection, if the problem persists then review the settings of any installed security software that may be interfering with the process. For more information on Error 126 see https://helpx.adobe.com/creative-cloud/kb/troubleshoot-download-install-logs.html#error126.
I¹m very sorry, but I checked all security software and there is no point which will prevent the download of the DreamWeaver-Update. Even then I stopped all this software (i.e. Little Snitch, Total AV etc.) the download failed with error 126.
Now I thought the error could be due to the old version of DreamWeaver CS6 an I started the uninstall App. But after this, DreamWeaver got lost in the installed applications of Creativ Cloud and although not included in the Apps of my Abo.
Thank you for the update, Werner. If the error is not related to installed security software, then it may be fundamental as a problem with the Internet connection.
Please try downloading the software using an alternate Internet connection. If you are on WiFi, try using an Ethernet cable to connect to the network. If you are already connected via Ethernet, then try using an alternate Internet connection from your phone or some other source, to see if Error 126 persists.