This article contains information on the breaking change with dot notation.
In Episerver CMS 7, the code was using a version of Dojo that had its own synchronous loader which used dot notation.
In Episerver CMS 7.1, changes with Dojo dependencies forced the use of slash notation.
Up until Episerver 10, there was extra support code to assist customers moving forward to slash notation.
This issue would present itself with edit view load issues and hang ups. Errors in the browser console would look like the following:
404 error - failed to load
This is followed by internal errors in dojo.js and widgets.js, which seem to be caused by the above error.