OSX 10.10.4 - External Monitor update
 

Apple just released an update to OSX and it includes an external monitor update.

I had been using the previous driver release (right before the latest July 3rd version) and when I updated OSX, I could not get past the boot up login screen.

The screen kept flickering as if there may be some kind of monitor issue. Wanted to give everyone a heads up to maybe take a look at the release notes from 10.10.4

The OS X Yosemite v10.10.4 update improves the stability, compatibility, and security of your Mac.

This update:

- Improves networking reliability
- Improves Migration Assistant reliability
- Addresses an issue that prevented some external displays from functioning properly
- Improves the reliability of upgrading iPhoto and Aperture libraries to Photos
- Improves reliability when syncing photos and videos to iCloud Photo Library
- Addresses an issue that could cause Photos to unexpectedly quit after importing some Lecia DNG files
- Resolves an issue that could delay outgoing email messages in Mail
- Fixes an issue where a website could prevent the user from navigating away by presenting repeated JavaScript alerts in Safari

No idea if this caused the conflict, but very well could have been.