The problem is encountered when using the extension installer/uninstaller
weectl extension. If you install WeeWX v5 via a package install and then use
weectl extension install to install an extension, some or all of the extension files may be installed in an incorrect location. At this stage nothing destructive has occurred to your system other than the extension files perhaps being in the wrong location (and almost certainly the extension itself will not work with WeeWX - though WeeWX functions normally). If you then happen to uninstall the extension (perhaps because it seemingly does not work) with
weectl extension uninstall that is when the uninstaller might delete system files.
So in these circumstances we recommend against installing or uninstalling extensions with weectl extension. Manual installs/uninstalls of extensions will be fine, it is just weectl extension that experiences problems. Also, if you have upgraded from an earlier WeeWX package install and the extension concerned was already installed (ie it was not installed using weectl extension) then you will be fine.
This issue will be fixed in v5.0.1 which should be released real soon.
Gary