There is something you can try to see if there is an issue with the installation of the extension. Locate the cache file and delete it, then restart your machine and try it again. If the problem persists it may be an issue with the configuration folder. Just to be sure you should also try the step of removing this configuration folder to see if it gets you past the issue. If not I will need to do some testing and look into the issue further with you. Here is a link to a page that contains the steps to for both of these:
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