RNBO 1.4.3 refuses to start
Similar to a previous thread: I was unable to do RNBO work because max suddenly refused to edit, create or open RNBO.
The console error was "Could not connect to RNBO buildserver" and several other errors including "Unable to get gRPC URI and WebSocket port from codegen server". After a day of frustration investigating network, firewalls, packet captures etc, I tried repair and reinstall, which didn't fix the issue.
Then I deleted (Username)/AppData/Roaming/Cycling '74
This fixed the problem (so far!). As detailed earlier by NUMB_CHANNELS in the thread https://cycling74.com/forums/rnbo-130-refuses-to-start
I hadn't had any crashes or issues or software updates, so I don't know how anything got corrupted in the Cycling '74 files.
I hope this will help others who run into the issue.
Same problem here. Solved it once yesterday by reseting the whole MAX by deleting and installing again. Today I am back to the same problem again.
Edit: I did the similar but on Mac by removing the Cycling74 files in the library. Then it works for now.
Just hit this same issue and wanted to add a less destructive fix, since deleting the whole Cycling '74 folder costs you your authorization and all your settings.
Symptoms: Max froze for a couple of minutes whenever I opened RNBO or a patch containing an rnbo~ object. After the freeze it eventually loaded, with this in the console:
rnbobuildserver: Unable to get gRPC URI and WebSocket port from codegen server
could not initialize RNBO classes, no response from server
error 13: Failed to create client channel
could not retrieve target API version
Could not connect to RNBO buildserver !
rnbo~: rnbopatcher extension not found, editing of rnbo patchers disabled
What did NOT work: rebooting, reinstalling Max, checking the Local Network permission in System Settings, and confirming Max and RNBO were both on the latest release.
What DID work: deleting a single file, preferences-cache.json. On macOS it sits at the top level of ~/Library/Application Support/Cycling '74 — not inside a version subfolder, so it's shared across Max installations. Quit Max, delete or rename the file, relaunch. Max regenerates it and RNBO starts normally.
Note that the user Library is hidden by default. In Finder, press Cmd+Shift+G and paste the path.
This also explains why a reinstall doesn't help — reinstalling replaces application files but never touches your user config, so the bad cache file survives it. Deleting the entire Cycling '74 folder works because it takes this file with it, but it's a blunt instrument for what turns out to be one corrupted JSON file.
Credit for the fix goes to the #rnbo channel on the Cycling '74 Discord — original message here (you'll need to be in the server to see it): https://discord.com/channels/289378508247924738/1218229779954925588/1524464598848245830