An mdex file extension is related to the Mifos Data Exchange XML data format.
MDEX file extension - Mifos Data Exchange XML data
What is mdex file? How to open mdex files?
File type specification:
The mdex file extension is used for files written in the Mifos Data Exchange XML based language.
Seems to be very rare used or obsolete file format without support from developer.
This mdex file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.