A cpxml file extension is related to the IBM Research nad used for some kind of data files.
CPXML file extension - IBM Research data
What is cpxml file? How to open cpxml files?
File type specification:
The cpxml file extension is associated with IBM Research (IBM ABLE).
The cpxml file specifies the state machine and the names of message schemas used.
The IBM Research software seems to be obsolete product.
This cpxml 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.