When using keyword planner I like to add keywords to a plan, then sort offline and build ad groups manually.
Looks like Google has accidentally or purposefully withdrawn the ability to download the plan to a spreadsheet. The only option I can see now is 'create ad group'.
Anyone else seeing this?
ADDED:
Hopefully a bug. If you try to 'resume' an existing plan it takes you to a daily forecasts screen which cannot load properly. Oh, and you lose your 'saved' keywords too.