I had the same problem, here is how I fixed it. First I called my hosting company, Hostgator because the problem also affected my wordperss login screen, in fact there was no login screen. First They deactivated all my plugin's. Finally I was able to at least log in again. then when I reactivated it, it did the same thing.
I called them back and luckly every week or so they back up the website. It cost $15 for the restore but it was worth it. restored everything back to the way it was before the woocommerce update. After that, I contacted Cheope about this and here is how it went:
I updated the woocommerce plugin and it totally messed up my entire site. In order for me to even be able to login to wordpress, I had to delete the plugin from cpanel, now all the 300+ products I put in are gone! Why did the update do that?
I do not know what happened so that your products are lost, but know that the style messed up was a temporary issue. I see that you have cheope 1.4.0 that is not compatible with WooCommerce 2. You have to update Cheope theme as well to the version 1.5.0 to get all working correctly.
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So I guess the proper way to do it is to first update Cheope, then woocommerce. I have not done that as of yet. I want to finish putting all the products into my site the way it is, make a manual backup of my theme and site, then I will update Cheope and woocommerce, so if it happens again i know that I can at least have my site back the was it was before the update.
Hope this helps...