Capture, explore, gain understanding of ideas

File format change

One of our large customers ran Decision Explorer through some testing processes to check if it was vulnerable to attack. Thousands of tests, and some of them showed that Decision Explorer could have problems with files modified in interesting ways. Mostly you could cause it to hang on loading, and we’ve never seen files with any problems, but they needed more assurance. And so we have promoted the existing XML file import and export to be the primary file format as of version 3.5.

What has changed?

Most people will carry on as you always have. All your existing models (file extension .MDL) will be there and load as before. New models will be saved using the XML based format, with a file extension of DEXM. (This new extension also helps to stop conflicts with other applications using .MDL.) You can save a model using the old binary file format using the file type selector in the file save dialog, if you want to send a file to someone using the old version.

Special situations

If you are in an organisation that needs to use a strictly more-secure version, then we have an XML Only build that will not load or save the binary files at all. (The standard build can also be told to not load binary using a registry change, which is handy for testing or transferring models between formats.)

If you really don’t want to have the better XML file format at all, then you can use a binary only build. We do not recommend this version, and it will be phased out.


The download page for the software has the various versions displayed, along with the previous 3.4 version. When you install, you are shown the version that will be installed. This information is repeated in the About dialog, so you can confirm your installed version.

“XML” – standard version

“XMLO” – a version that cannot read the binary file format at all.

“Binary” – a version that cannot read the XML file format (except in import mode which is not so easy to access).

The Viewer and Demo versions will be updated with the new XML tag too.


If you have any questions on this, please email us at info @ and we will do our best to help.