Problems from old config files

Old KDE config info continues to cause problems: 1) chromium-browser simply wouldn't work for me (as discussed on another thread). The spinner span and browser said "Connecting ..." and nothing ever happened. 2) I can't switch user sessions from my normal login. I get a grey pop-up box with no message or selection list. The only thing I can so is close it. When I log in as a test user (also in KDE), both of these work immediately with no issues. Clearly the problem is old config files, but which ones? How is the user supposed to know? This kind of thing has been a problem with KDE since I've been using it -- many years now -- but it doesn't seem to happen with other desktops such as Gnome (or am I being naive?). We clearly need a way of dealing with this. I guess transparent updating is a lot to ask, but at least detecting obsolete config files and warning the user should be a high priority for future KDE releases. Would it be too hard for each config file to include a comment line at the beginning with the version of whatever KDE component created it, and new versions of that component to check the line for compatibility? poc