I just updated my configurable tag cloud plugin to version 5.0. The big news in this version is the widget has been brought up to date with the new Widgets API released in WordPress 2.8, and you can now limit the tags displayed in the cloud by the number of posts attached to each tag. This will stop the issue of having a few tags that overpower the cloud.
I haven’t updated the CTC page yet, so for now, you’ll need to either use the WordPress plugin update feature, or visit the plugin page at WP Extend to get the new version.
I tried installing directly from my WordPress blog itself using the internal plugin finder and installer. Initially it gave me the same error. But moving the tag_cloud from within the parent folder got it working properly.
Hope this helps.
I've got the same thing here
the plugin does not have a valid header
I have the same message as Joe after installing from within WordPress. It does not appear in the plugins list, but if I try to re-install I am told I already have it. Going to try deleting the folder and upgrading manually.
All works OK now after a manual install.
I tried to install this plugin today. It uploaded successfully but when clicking 'activate plugin' it brings up an error:
The plugin does not have a valid header.
I'm not sure why you would have gotten this error. I've done a dozen or so upgrades (using both the manual method and the automated method via the WP admin panel) and none have cause any issues. Try removing the tag_cloud folder (and the tag-cloud.php file if it's there) from the plugins folder via ftp and try uploading it again.
If it doesn't work after doing that, drop me a line via my contact form here and I'll see if I can help you get up and running.