Setting the location is not possible anymore, since search location does not return any results. Debug message from the panel says: (wrapper:1976): weather-WARNING **: Unable to detect the content length. when executing a location search. Although the xml returned from openstreetmap list correct locations.
All versions <=0.8.2 use a native HTTP client that has problems with HTTP/1.1 chunked transfer encoding, resulting in the error message you see. I guess openstreetmap must have changed something about their server config recently and now the search no longer works. There may be a simple way forcing HTTP/1.0, but I'm not sure the plugin's not already trying to do that, anyway the server may not respect it and still use chunked transfer encoding. Git master uses libsoup which fixes this problem and other severe issues. You will have to compile from git, wait for the next 0.8.3 release or someone needs to backport the patches (there are several though, committed on ~2012-11-20). As a workaround, you could enter latitude and longitude in the plugin rc file manually (~/.config/xfce4/panel) and restart the panel with xfce4-panel -r.
I think it's a good idea to leave this bug open until 0.8.3 gets released. That way, people can see it on the goodies homepage and when they search for it.
*** Bug 9639 has been marked as a duplicate of this bug. ***
*** Bug 9638 has been marked as a duplicate of this bug. ***
The workaround Harald Judt suggests doesn't work for me. (Xfce 4.8 on Fedora 16.) Checking, the old config file containing only the wrong location overwrites my changes when I run xfce4-panel -r. However, keeping the file open in mousepad, resaving it and trying again finally worked on about the third try. I don't know what changed that time, but I did want to report that the fix doesn't always work the first time.
Probably the config file is saved on panel exit too. You can always close the panel with "xfce4-panel -q", edit the file and then start the panel with "xfce4-panel &". I guess you could also get the location search going by using a proxy server, but I haven't tried that.
Also note that only latitude and longitude are needed to fetch weather data. Location name can be changed to whatever you want and does not have any effect on the coordinates; it is only used for display.
Changing the location name is fine if the lat/lon are close enough and the data returned is right. In my case there are mountains between Newbury Park, CA (what it finds) and Camarillo, CA where I live. There's a significant difference in the weather, especially because I'm closer to the ocean and at a lower elevation.
0.8.3 has been released and fixes this problem, closing this bug now.
I just installed this plugin on my laptop. It picked up my current location (at home) correctly. Good. I tried to have it add a second location and it failed to return anything for Van Nuys, Simi Valley, Hollywood or Salt Lake City. As I use this machine when travelling, I'd like to be able to add locations that I'm planning to go to so that I can get a forecast in advance. Not Completely Fixed, unless it's not supposed to be able to do this. (If this is the case, a mention in the documentation would be appreciated to keep people like me from expecting too much from it.)
0.8.3 can find all those locations you specified. So you're doing something wrong, or maybe you happen to have installed an old version? Do you still get the warning as reported in Comment #1?
I have the most recent version available from the Fedora repos: 0.8.2-1. (Until you asked, I had no reason not to expect the repo to have the current version.) Checking, the newest version isn't even in our updates-testing repo yet, so I'll just have to wait. Thanx for asking about the version number.