SIMATIC WinCC Open Architecture Forum

Environment
Windows 2016 Server
WinCC-OA 3.16 p20
Windows 10 workstation

Recently we have discovered a problem with a windows-environment which runs an application which is viewed via a desktop-UI client. The desktop-UI is not able to switch from a Dark to a Light theme anymore. After some checks we discovered that the Cache folder at server-side had converted some 'folders' from the project to a .gz file. instead of keeping the folder as folder.

e.g. (environment with a problem)
<project>\colorDB\NightScheme (folder) -> <project>\cache\colorDB\NightScheme.gz (file)

e.g. (environment without a problem)
<project>\colorDB\NightScheme (folder) -> <project>\cache\colorDB\NightScheme (folder)

We tested the same application on a different environment which does work as supposed to be, so we suspect a setting somewhere in our IT environment to be wrong, but have no clue in which direction we need to search.

The IT environment is not controlled by us, also they maintainers have no clue what could be a cause, in their words "nothing is changed". So I would like to ask if someone has seen this behavior before, and maybe found a resolution for it?

Thanks, in advance.
Gr. Michel.

I have made test with 3.17, in 3.16 the behaviour is possibly the same.
When files are transferred to the Desktop-UI they are compressed as gz files. The compression is only made for files but not for folders.
With the debug flag "-dbg http" for the script webclient_http.ctl you can possibly get additional information for the compression of files before copying them to the client.

Best Regards
Leopold Knipp
Senior Support Specialist

The cache compression can be disabled with the 'httpServer' config entry 'compressionCacheEnabled'.