Addon domain addressing
PermalinkUsing Version 5.6.2.1 because the following updates brought error messages. These errors messages were years before the addon domain issue.
Asked hosting tech support for help with addon domain issue, found no problems on their end and was told to contact Concrete5.
Hope you can help, it used to work.

I searched public_html/.htaccess and it showed an empty directory. I assume it's a hidden folder since I don't see it in the tree.
More search results for .htaccess shows:
/public_html/.htaccess.bak.1447297291
/public_html/.htaccess
/public_html/.htaccess.bak.1391316336
/public_html/files/backups/.htaccess
/public_html/files/tmp/1328151598/concrete5.4.2.2/concrete/libraries/3rdparty/securimage/database/.htaccess
/public_html/files/tmp/1328389382/concrete5.5.1/concrete/libraries/3rdparty/securimage/database/.htaccess
/public_html/files/tmp/1389512079/concrete5.5.2.1/concrete/libraries/3rdparty/securimage/database/.htaccess
/public_html/files/tmp/1326001404/concrete5.4.2.1/concrete/libraries/3rdparty/securimage/database/.htaccess
/public_html/files/tmp/1415561823/concrete5.6.3.2/concrete/libraries/3rdparty/securimage/database/.htaccess
/public_html/files/tmp/1328151623/concrete5.4.2.2/concrete/libraries/3rdparty/securimage/database/.htaccess
/public_html/WWdocs/.htaccess
/public_html/concrete/libraries/3rdparty/securimage/database/.htaccess