Plug-ins don't appear in Logic 10.5, Premier Pro 2020, Audition 2020, Cubase 10, Wavelab 10 on MacOS?

With some of the latest DAW releases on MacOS, our older plug-ins (Power Suite v5, Master Restoration Suite v5, and Dialog v1) do not draw. The plug-ins process audio, but the graphical user interface is blank, showing a black or grey window. This appears to be an incompatibility between the SDKs used to build our old plugs and the later SDKs used to build the DAWs. Apple is always phasing out support for legacy systems, for example, 32-bit code. There is unfortunately no easy workaround. We are rewriting all the older plug-ins to use modern Mac SDKs. Power Suite 6 and Dialog 2 are complete, and Master Restoration Suite 6 is in progress. These will be paid upgrades (65% off list) owing to the large effort required to rewrite everything, and the fact we haven’t charged for a Power Suite upgrade since 2005 when v5 was released.