I wanted to examine my .kmy data file with a view to possibly being able to do bulk edits on tags etc. I gunzipped the .kmy file to produce what I expected to be a stock xml file and tried to open and examine it. QXMLEdit reported an error when I tried opening the xml file (error message attached as qxmledit_error.png) KDE's kate reported an error and trying to read the xml file in Python3 using xml.etree.ElementTree module reported an error at the same place as QXMLEdit. Examining the line reported in error I have found that there is a character 0 embeded in this line at the position shown in qxmledit_error.png (i.e. between the 'k' and the double quote). I should report that kmymoney works perfectly well with the original .kml file but you may want to be aware of this in case invalid characters like this cause problems further down the line.
Created attachment 124741 [details] QXMLEdit Error Sorry, forgot to attach the screenshot - here it is