i use a local installation of Owncloud 8.1.12.2 on my Windows Server 2012 R2 with Xampp.
Today I wanted to log in but I suddenly get the message: Microsoft Windows platform is not supported.
I can't log in anymore. I know the newer OC releases are not supported on Microsoft Windows, but why the hell is my installation now no longer usable?! Are there any tricks so that it works again? The owncloud is not available from the Internet so Security Gaps do not matter.
Since 8.1.0 ownCloud is fully unsupported on windows. This is since ever and the first release of 8.1.0. Additionally 8.0.0 was also already unsupported [1] on windows.
There is currently no way to get ownCloud to work on windows as oC 8.0.0 is unsupported since a few months and won't receive any updates or security fixed. Please move your installation to a linux based host and install a fresh ownCloud 9.1.4 is you want to continue using ownCloud.