System Error: Cannot Supply Requested Class Factory

By "64-bit systems" do you mean Office, Windows or both?

My theory:

Treeview isn't one of the Office-supplied controls, I'm fairly certain.  It comes with Visual Basic ("classic") and possibly other languages.

In order to be licensed for use, the package that supplied the control would need to be installed on the PC.  If the control itself is registered, that'd permit it to be used by an app but not in design mode. 

Whether it works at all in a 64-bit environment is another story.

What's making this so strange is that up until today the control was working just fine. Then, I come back the next day and now it isn't. I didn't make any changes to my system and I can edit the project fine on other computers. Obviously something in my registry is corrupted. Perhaps the only solution is a reinstall of office.

By 64 bit I meant my operating system. But that doesn't appear to be the cause, as I have verified the project works on another identical system.

>> What's making this so strange is that up until today the control was working just fine. Then, I come back the next day and now it isn't. I didn't make any changes to my system and I can edit the project fine on other computers.

Ah, I must have missed that part.  That IS weird.

Did a bit of googling on just the error message (and various bits of it) w/o much in the way of useful results.

Have you tried unregistering the control then reregistering it?

I'd UN register the control then delete it before reinstalling, or at least rename it and put a copy someplace safe in case you need it back later.

If an update from MS delivered an incompatible version of the control, it'll be newer than the one the installer adds and won't be replaced.

I should also mention that this is not isolated to PowerPoint. I can't use this control in any of the office applications. I've run a registry cleaner and even tried to manually reregister the .OCX file, but nothing has worked. I'm wondering if I need to reinstall...

If you have an older version of MSCOMCTL.OCX than the template wants or if this file was overwritten may be at the root of your problem.  

First things first, Update your build of MSCOMCTL.OCX to at least this version 

http://support.microsoft.com/kb/957924

Your version of MSCOMCTL.OCX currently installed may not support the new CLSID that was saved in a VBA project, it may only support the old one which was “kill-bit'ed” per this security advisory

Microsoft Security Advisory (969898) - Update Rollup for ActiveX Kill Bits

http://www.microsoft.com/technet/security/advisory/969898.mspx

That would cause the error

"System Error &H80040111 (-21472211231) Cannot Supply Requested Class Factory."

"Out of Memory

Fixing the issue should be pretty straightforward. 

1.  http://support.microsoft.com/kb/957924

2.  Reinstall (http://www.microsoft.com/technet/security/advisory/969898.mspx) or a later version that is greater or equal to build 6.1.98.16.

**Note after you install the patch (and documented in the KB), you  may  need to scan and remove any  *.exd files found under each user profile (Under Temp and Appdata directories).

Sincerely,

Susan

Microsoft Community Support