so, after much nagging - eg, https://www.avrfreaks.net/comment... - I have updated Atmel Studio 6.2 beta (with ASF 3.16.0 beta) to the latest & greatest:
ARM GCC Toolchain 18.104.22.1687;
I can open my Project, and it builds successfully.
But, when I go to the ASF Wizard, it correctly shows v3.16.0 selected, but says that I have no modules installed - which is rubbish.
When I go to the 'Versions' tab, and select 3.19.0 to upgrade, it tells me that I have local changes - which is true.
When I press the 'Update' button, it churns for a while, finishes the process - but the report says it did nothing.
Sure enough, it has done nothing!
So how do I get it to actually do the upgrade?