CentralFileCommunicationException in OpenAndActivateDocument with OpenOptions

var openOptions = new OpenOptions();
openOptions.DetachFromCentralOption = DetachFromCentralOption.DetachAndDiscardWorksets;
uiapp.OpenAndActivateDocument(filePath, openOptions, false);

I'm getting an exception preventing me from opening the file.  CentralFileCommunicationException: "The file-based central model could not be reached, because e.g. the network is down or the file server is down."

I want to detach from central and discard worksets, so why is it trying to communicate with the central model?  How can I avoid this exception?