Hello DNN Software Forums,

I manage several DNN sites and have had this issue occur on just a handful of them, almost randomly.  The issue is when you attempt to enter edit mode, the modal login popup appears prompting for a login.  If you close out, it sometimes logouts you and sends you back to your home page (or 404), or it just leaves me on the page in edit mode.  There are no Errors generated in the DNN Event Viewer.  The only error I can spot is in the browser developer console which reports a '401' to the 'domain.com/DesktopModules/internalservices/API/controlbar/ToggleUserMode'.  It occurs with any user as well.  The interesting thing is that this only occurs on very specific pages and is never site wide.  Also, this appears to mostly only affect child portals, and if I'm not mistaken, only on DNN 8 and above.  In the past I have found that it appears to be caused by individual modules, however, the same module works on other pages.  To resolve all I had to do was simply 'save' the module in its settings.  Easy, but this does not always work and sometimes involves removing the module completely.  I've checked the module permissions and they are correct.  I've checked environment permissions and they are also correct.  This is affecting different installations across different servers, too.  We've tried all the basic troubleshooting tips, but none shed much light.

I am posting here for your thoughts on what to check, and if anyone else has come across this issue.  I suspect there is a conflict in the database for the module but I am not sure where it may be or why it would just happen.  We are very 'DNN' savvy so please do not dumb down any answers or insights.

Thank you!