update from 14.4.? to 15.0 error message InvalidZipFilePossibleNoConnectionOrFirewall

i just gut the update from 14.4.? (i do not remember 14.4.2 or 14.4.3) to 15.0 stable. after restarting portableapps i get the error message below. i have no clue where to dig in. all fixes published here for this problem do not apply. tls 1.1 and 1.2 are enabled on my system.

temporarely disabling windows firewall does not have any effect.

i am on windows 10 x64 build 17666. everything worked fine before updating to 15.0. installation of a freshly downloaded 15.0 over existing installation did not work out either.

thanks for this jewel piece of software. can´t wait to see it working again

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PortableApps.com Platform
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Unable to connect to PortableApps.com to retrieve portable apps. Please try again later. [ InvalidZipFilePossibleNoConnectionOrFirewall ]
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OK
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or in german (as i use it more often in german)

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PortableApps.com Platform
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Es konnte keine Verbindung zu PortableApps.com aufgebaut werden, um Aktualisierungen der portablen Anwendungen herunterzuladen. Bitte versuchen Sie es später noch einmal. [ InvalidZipFilePossibleNoConnectionOrFirewall ]
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OK
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