Over 3 years ago we migrated to Office 365, as part of that process we decided to allow self service site creation. To that end we used a provider hosted app which could be accessed from Sites -> New Site which is changed to SharePoint -> Create site. This has worked well for over 3 years until now.
We used the technique set out in Richard diZerega's blog here. So the issue is that the technique uses a postMessage to the parent to resize, close the dialog that has been opened from Create site, if you don't do this the standard size of the dialog is way too small, see below:
Looks okay for the first page, but on the next when I have to enter details about the site (url, description, department etc.) then I have to scroll to get through the form.
This changed sometime in December 2016, I presume the event listener in the parent has changed or been removed, anyone know why and have any details on how this issue can be resolved?