Dear slash,
I have tested this on my end, it works fine.
Please follow steps:
1. Open "CuteSoft_Client\CuteEditor\Configuration\Security\Default.config"
2. You will find the following section:
<security name="DocumentFilters">
<item>.txt</item>
<item>.doc</item>
<item>.pdf</item>
<item>.zip</item>
<item>.rar</item>
<item>.avi</item>
<item>.mpg</item>
<item>.mpeg</item>
<item>.mp3</item>
<item>.wav</item>
<item>.swf</item>
<item>.jpg</item>
<item>.jpeg</item>
<item>.gif</item>
<item>.png</item>
<item>.htm</item>
<item>.xls</item>
<item>.html</item>
<item>.rtf</item>
<item>.wmv</item>
</security>
Please change it to:
<security name="DocumentFilters">
<item>.docx</item>
<item>.txt</item>
<item>.doc</item>
<item>.pdf</item>
<item>.zip</item>
<item>.rar</item>
<item>.avi</item>
<item>.mpg</item>
<item>.mpeg</item>
<item>.mp3</item>
<item>.wav</item>
<item>.swf</item>
<item>.jpg</item>
<item>.jpeg</item>
<item>.gif</item>
<item>.png</item>
<item>.htm</item>
<item>.xls</item>
<item>.html</item>
<item>.rtf</item>
<item>.wmv</item>
</security>
4. Click "Downloadable Files" button
5. Click "Upload" in dialog
6. You will find "docx" are visible in file filter list.
Thank you for asking