We have had a problem recently with a Developer Studio user in our Australia office attempting to connect to our Server in the United States. When attempting to connect, they receive a (WFC 701) NULL error. I can't find this error code anywhere, so I don't know where to start looking for the problem. Has someone out there had this problem that can point me in the right direction?

If you search in Techsuuport, you will find two entries.

One is a Hotfix that contains a fix for:
Dev Studio:WFC701 Null error expanding Projects on Localhost (DeployView.dll, gcMscTls.dll, gcdialog.dll, fshtmlpage.dll, WFSCom.dll)

If this does not work, I would suggest submitting a case with Techsupport.
The other is when the parameter IBIF_adhocfex has been enabled.

The suggestion for this is to:
This issue was resolved by restoring the default value of IBIF_adhocfex in
the ibidir.wfs file. The default value is:
# IBIF_adhocfex(protect)

If this variable is enabled, it is not possible to run an adhoc query.