msmcleod

azslow3
If you ask me, the root of the problem is in the internal numbering. They do no use "category":"source", but just "source" in projects. So when some category changes in size, f.e. the number of hardware MIDI inputs, all input specifications at all places should be "shifted". And it seems like they not always do this correctly.
The latest CbB update claims there are some fixes in that re-numbering, but I see reports the fix is not ultimate.

I've always hated the way MIDI device numbers are used in Sonar/CbB and constantly change depending on what is plugged in. I quite often load projects between machines, which have different MIDI devices and whilst it's less of an issue now since I mainly use VSTi's, older MIDI hardware based projects are still affected.

To avoid confusion...
You never see this internal numbering. It is "internal" 
And while your problem is somehow related, that is not what course VST MIDI outputs mess with (hardware) MIDI inputs.
 

To my mind, it would be better if the source number had an extra level of indirection, so the number was a reference to a numbered MIDI device "slot" which is persistent regardless of whether the device is present or not.
 
In other words, you'd define what MIDI devices occupy which slots and this would be stored in your config. Different machines could have different configs, but as long as the slot has an assignment the project should be fine.
 
If you loaded a project where the MIDI device is not there, you could temporarily re-assign it to another device, or choose to leave it unassigned.

A good idea. And... surprise! CW also knows it is a good idea. They ARE saving that indirect mapping into projects. So everything can and should be fine. If whoever has programmed related processing could manage to do this correctly. But he has not managed