"The changes have not been applied. The resulting flight plan would be invalid." when transferring flight plan...

THe warning message does not provide any details about what's wrong or how to correct those error to make the flight plan transfer work.... I was trying to transfer a flight plan from ATR to SSJ and a quick scan seems to show the problem is with some flight's depature/arrival slot, and the increased speed would mean some flights would be affected by the night time restriction. How to correct those problems to facilitate a correct migration and is there a way to check everything that is wrong?

Personally if this happens I untick "only transfer without errors", then I find the problem, if it's fixable on the new aircraft, fix it, if not transfer it straight back

In fact, I'd prefer if there was an option to disable "only transfer without errors" by default. It's a pointless option anyway as you need to transfer before you can know what's worng, but it's a hassle to have to click on it every single time.

It supposedly served the accidental transfer to aircraft with existing flight plan.

But this option could be replaced by Only Transfer if Flight plan does not overlay.

Usually people transfer the flight plan back if they can’t adjust the errors after transfer.

And the safety belt can be replaced by the existing flight overlay warning.