'GCVirtualController?' has no member 'changeElement'

In the example code:-

vc.changeElement(GCInputButtonA) {

I get the error. Value of type 'GCVirtualController?' has no member 'changeElement'

I thought the vc reference was view controller but this did not work.

Any help would be great.

Thanks in advance

'GCVirtualController?' has no member 'changeElement'
 
 
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