Game stuck trying to rebase overrun convoys

[carpenkm]

Ive just captured Oslo and have 13 convoys there being overrun. I can only rebase to Kristiansand (presumably wont let me into the North Sea because Germany controls Denmark).
When I destroy overstacked convoys the game hangs on Over-Stacked digression. I cant see anyway to proceed. Is there a way to reactivate the green proceed button or manually destroy the convoys before they have to rebase?
Any help gratefully received.

[paulderynck]

Try selecting the overstacked number of CPs and with them "in hand" press the backspace key. You may have to breakdown the CPs to make this manageable.