After installing the newest version, I receive this diagnostic.  Not sure at all what it means.

 

There is no applicable method for the generic function:
  #<STANDARD-GENERIC-FUNCTION ENSURE-COMPOSER-PANE #x302001CFAA4F>
when called with arguments:
  ("/Users/RSTGSU/Opusmodus/Extensions/Load CLM Instruments.lisp" #<OM-LAYOUT-CONTROLLER <OMLayoutController: 0x735e90> (#x735E90)>)

 

Nor do I know how to solve it.

Looks like you are not using CLM therefore remove the 'Load CLM Instruments.lisp' form the Extensions folder, otherwise follow the instruction how to make the CLM work here:

 

Thanks a million!