Just in case any of you are dependent upon this great little tool, a heads up that it will not run with MacOS Catalina as 32-bit application capability has been dropped by Apple.
MIDI Patchbay was written back in 2008, and I would not expect the developer to produce a 64-bit version.
On a positive note, there is good news for any of you who are happy with a bit of software engineering. The source code is available in GitHub.
I rebuilt it as a 64-bit application and now have my 64-bit version of MIDI Patchbay working perfectly in Catalina.
Along with build configuration, I did also have to recode it just a little, but it really wasn’t a big deal. Before you ask, I can’t (as opposed to won’t) share the new app with you, as I don’t have an Apple Developer Community licence, so had to code-sign it for my own personal use.
Hope this helps someone.