Error -9939 occurs when launching Modulus once the password has been entered.

The usual cause is the absence of a Mac4DX folder (Macintosh) or Win4DX folder (Windows), which results from installing Modulus but not the support files. Alternatively, the contents of the folder may not be complete or correctly named.

In single user installations, this folder should be placed in the same folder as the Modulus application. In multi user installations, it should be on your server, again in the same folder as the Modulus application. If you have both Macintosh and Windows clients, you will need both Mac4DX and Win4DX folders present on the server.