After upgrading to “openHAB 2.2.0 Build #983” from OH 2.1 my default sitemap stopped working. In the logs when I change something it does not list any issues just “Refresh sitemap”…
In order to troubleshoot I copied _default.sitemap to _default2.sitemap and was able to successfully load it in Basic UI and Classic UI, while _default.sitemap just shows a bunch of things rather than loading the sitemap file.
I wouldn’t use the name _default for a user defined sitemap. This name is already used internally by openHAB2 and it is created dynamically to display your Things (for example in the control tabs of PaperUI)
Create a new file called master.sitemap in /etc/openhab2/sitemaps/ and use the same name as the filename: