Two days after so-called stable version 6.9.4 was released, I attempted to upgrade to it. The upgrade installation failed and I got a white screen of death. I was devastated. Eleven years of work was posted on my blog and it appeared to be lost to me forever. A developer suggested I ask my host to restart my account to a time just before the failed upgrade, which I did. However, I found out yesterday, when I tried to post for the first time since recovering my blog, that the post button, as well as the collection button next to it, were grayed out. Even though I found another button I could use to post, I found once I did that I could not upload new images or files to the post by browsing my laptop documents and downloads because the blue bar was missing. The existing b2evolution directory of images were all dated November 29, when I recovered my blog, but I can't insert them either. The analytics are still working, and apparently I can still post, albeit with an alternative button, but I need to fix my site or I can't solicit advertising for it. Can I reinstall version 6.9.3 to correct the corrupted version I now have of my site? How do I do that?