Just proceeded to install X1a then X1b patches on X1 (64bit).
 
However, at the end on X1b patch, I got 2 error messages which I almost had no other choice than ''ignore'' :
 
This seemed to be related with shared plug-ins:

''Unable to register the DLL/OCX:RegSvr32 failed with exit code 0x3. Click Retry to try again (which of course never work...), Ignore to proceed anyway (not recommended), or Abort to cancel install''.
 
Anyone had this too ? Is it caused by fact I still have 8.5.3 (both 32 and 64 bit versions) on my system (and work mostly with these yet...)?
 
Rob

Same thing happened to me applying X2a patch. I checked on Microsoft's help pages and they said to right click on the .exe icon and run as administrator (Windows 7). Installed just fine then.
Steve
 

Make sure that you run setup program as an administrator.  I have also found that running Sonar after upgrading the first time as admin makes things work better.  You have to do some setup things more than once when you do this, but I have found that I don't have as many UAC issues if I run as Admin the first time after an upgrade.

Glen

By the way.

Run as administrator.

Error code 3 means "path not found", FWIW. It was attempting to register a DX plugin and either couldn't find its expected folder or the folder of a dependency. You can safely ignore the error and proceed with the installation. The only repercussion is that one DX plugin won't work, and you may not find out which one until you open an old project that uses it. And if you've never used it, well, then there's no problem.