I was moving some custom code into a customer’s development environment when I noticed what I consider a breaking change that I am assuming was added in Update Rollup 12.
The URL field on an iFrame’s properties is now converted to a fully-qualified URL.
Imagine starting with this:
Here we have a custom ASP.NET web page located in the ISV folder system.
If you edit this field’s value, it will turn into this:
Which is an invalid URL.
UPDATE: It gets worse. It seems that we can’t use the standard placeholder of about:blank either.
Note: This is only an issue if you edit the iFrame properties. If you leave them alone, you will not encounter this problem.