I've created an online installer containing this download section shown at the bottom.
Unfortunately I'm behind a firewall and so have to use a proxy. PortableApps is configured properly and can successfully download new applications.
But my Installer, created with PortablApps.com Installer 3.0.15 is not able to download.
As the details didn't tell me much (SendRequest Error), I've used wireshark to sniff the network traffic. It seems there is something going wrong. Please see a snapshot at http://img5.fotos-hochladen.net/uploads/wwwdbviscomppiewh972ql.png
As you can see, the full request URI, as seen by wireshark is "http://www.dbvis.comhttp://www.dbvis.com/...." which is for sure wrong.
[DownloadFiles] DownloadURL=http://www.dbvis.com/product_download/dbvis-9.1.11/media/dbvis_windows_9_1_11.zip DownloadName=DbVisualizer 9.1.11 DownloadFilename=dbvis_windows_9_1_11.zip DownloadMD5=e0a40b41da7217b5f53e6aae1d53faf0 AdditionalInstallSize=65500 AdvancedExtract1To=App\ AdvancedExtract1Filter=*