I tried installing it on my 435 this week, and twice it failed and I had to use Windows Phone recovery tool to get it back to 8.1. Is there a but preventing W10MTP being installed on this phone at the moment?
I had same issue here, i had tried so many solutions by removing sim/sd, installing on phone without any app, or after hard reset, always stucked in progress bar upgrade about 60%, and no solution. Note that before i was able to upgrade last time i did before 3 weeks ago
Same happened with mine. We shall have to wait for Microsoft to fix this problem which I'm sure they know about by now. No idea when the next build will be released, though.
I have heard of other models of phone doing this as well, not just the 435.