Google Chrome Dev version was updated to 3.0.193.0, there have been some breaking changes in the way Google Chrome installs an extension since version 3.0.189.0, this is a very important update, Chromium Team has been changed the way to package extension.
Extensions are packaged as signed zip files with the file extension "crx" (eg myextension.crx). With the old way, you must install Python 2.6+ on your computer and then download chromium_extension.py to package the extension. The new way needn't Python 2.6+ and chromium_extension.py, just do following steps:
1. Close all your Chrome windows.
2. Open a command line.
3. Type: <path-to-chrome>/chrome.exe --pack-extension=<extension-folder>
Screenshot: Package Google Chrome extension
If you've developed an extension, you can learn how to repackage your extensions for Chrome v 3.0.189.0 in the packaging doc on Chromium developer site. Note that your extension ID will now be your public key, so you'll have to change any code that uses that.
If you're using an extension someone else has developed, you will have to reinstall it once the developer has repackaged it (as described above). We've already updated our sample extensions.
I just updated PageRank Status to version 2.0, it's compatible with dev version 3.0.189.0 and 3.0.193.0 now.
New way to package Google Chrome extension