RW 6.4 won't install...& publishing question

I’m on 6.3.7, trying to Install 6.4 on my MacBook Pro running OS Sierra 10.12.1

Everything downloads fine from the Search for Updates menu, and extracts automatically. But then I keep getting this message:

What can I do?

Also I’m really not sure if my sites are publishing properly - I make changes which appear to upload OK when I hit ‘Publish’ but then when I check them online they appear the same as before. I’ve tried emptying caches/different browsers to no avail. Any suggestions?

Get it from here instead

When automatic updates fail:

  1. Download directly from the developer.
  2. Check out the version(s) you have installed – make sure there is only one.
  3. Check for any other anomalies.

Failed updates usually occur when, for some strange reason, the new file can’t replace the old one. This can happen for all sorts of strange reasons. Some that I’ve seen:

  • Multiple similarly named apps/addons exists and the updater can’t replace the right one.
  • The hard drive is full
  • The hard drive permissions are corrupted (this is not really a problem since macOS 10.11)
  • The admin password is required to replace apps – and is entered incorrectly