Such multi-channel input routing in free SPAN is possible in some audio host applications, and is possible in VST (not VST3) plugin format only. DAWs that offer this feature are Ableton Live and Cakewalk Sonar. In all other hosts you have to use SPAN Plus with its Import/Export spectrum options.
This may not exactly be Voxengo plugin's issue. Audio plugins work inside the audio host application in the shared memory space and so, if any plugin malfunctions this may cause a crash in an unrelated plugin. In this case the Voxengo plugin will not crash if you load it in an empty project using the same preset settings, or if you remove a malfunctioning plugin. We perform a very thorough automated testing before releasing plugins. In many practical cases the crash originates in another plugin. But anyway please send us the crash log.
This may not exactly be Voxengo plugin's issue. Audio plugins work inside the audio host application in the shared memory space and so, if any plugin malfunctions this may cause a crash in an unrelated plugin. In this case the Voxengo plugin will not crash if you load it in an empty project using the same preset settings, or if you remove a malfunctioning plugin.
We perform a very thorough automated testing before releasing plugins. In many practical cases the crash originates in another plugin. But anyway please send us the crash log.
As we have analyzed this issue over the years the source of this issue is not the Voxengo plugin, but some other plugin staying before it in the signal path. The reason for such behavior is the so called "NAN" ("Not A Number") values produced by a prior plugin which did not initialize its state correctly. NAN values then produce an incorrect behavior inside the Voxengo plugin, with the output level meter spiking being a usual manifestation of NANs.
It is a known issue with VST2 plugins in Cubase. You have to close and reopen the plugin window for the resizing to take effect. VST3 plugins do not have such issue in Cubase, so you may consider using VST3 instead of VST2 plugins.
This message may appear if you have more than one version of the same plugin installed at the same time, under different name or folder. This may also happen if you installed both VST3 and VST versions of the plugin and using them in the project interchangably.