Obviously there isn’t anything I can do to help you right now.
I know I said this:
Search this forum for the terms ‘white’ and ‘blank’. I know this type of thing has come up once or twice in the past.
But I also searched the forum and the incidents I was thinking of where totally different and unrelated to your issue.
So to answer your question: “Has this been reported elsewhere?” Sorry, no.
It seems to me that you must be doing something wrong during the installation process.
My advice is to create a copy of your current database, install 1.15.x in a different directory and using the copied db, and let it upgrade the db.
That way you can have a testing installation while keeping your production installation running.
Then fill out the Assistance Request Form again with the info on your testing installation and I will take a look (section 3 of the form would be really helpful, if possible, so that I can look at your error logs as you did not report back on that when I asked).
I will mark this resolved for now but feel free to report back at any time.