Hi Boxandrocks -
Are you using the Github version of the engine? If so, have you tried to recompile the engine source. If you are using the Launcher, click verify the engine and redownload if necessary.
Also a few users had issues with some out of date or corrupted Visual C++ Distrubutable Libraries and in particular this one, Download Visual C++ Redistributable Packages for Visual Studio 2013 from Official Microsoft Download Center. If you already have this Distbutable I recommend uninstalling and not just repairing then reinstalling from the link above.
Finally, open Swarm Agent directly (via the …\Engine\Binaries\DotNET\SwarmAgent.exe) and clean and validate your Swarm Cache and ensure that the Swarm Cache Location has a significant amount of freespace (I recommend 30 to 40 GB, but it depends on the size of your project).
If known of these work for you, please open the Windows Event Viewer (search Event Viewer in the Windows Start Menu) and copy the error into an Event Viewer file, zip it up and upload a copy here.
Thank You
Eric Ketchum