Dear Chris,
this isn't rather a bug, i guess, but i am wondering why there always when i close MRICON an error message appears telling 
******************
Unable to create file
"...\mricron.ini"
Press OK...
Press Abort...
********************
?

And despite this message, that *ini-file will be indeed created and updated... 

I guess it is rather a win10-related problem?!

best, adam

1. If you select the file properties for the ini file, is the "Read-only" checkbox selected? You want a file you can both read and write, in a folder you can read and write. 

2.You may want to try upgrading to MRIcroGL (go here for a pre-release of the upcoming version). It will save your preferences in the user home folder, which avoids file permission issues. I will consider this for the next release of MRIcron. However, most of my efforts focus on my more recent tools (e.g. MRIcroGL) over legacy tools (MRIcron).

dear chris, 

thank you for the reply. no it wasn't the read-only-attribute.
and after observing some other weird behaviour (when repeatedly just double-click mricron.exe and close it immediately, the error-message sometimes appeared and sometimes not), i moved the mricron-folder from my dropbox and now it seems ok. i guess the dropbox-client was "blocking" the ini-file.

best,
adam