Hello,I know how to implement AURenderCallbacks in an AVAudioEngine using the audioUnits of the input or output nodes.In my new project, I would have to create an AVAudioUnit node to connect my AuRenderCallback to it, but whatever I do, this creation does not work: I read with NSLog "aUnit = (null)".I followed the advice in this discussion:https://forums.developer.apple.com/thread/39715My code is :AVAudioEngine *audioEngine; AVAudioPlayerNode *player; //I'll need a PlayerNode and a SamplerNode in my project AVAudioUnit *aUnit; //this one will analyse the audio of the playerWhen I create the graph (with AVAudioEngine) :[AUAudioUnit registerSubclass:aUnit.class asComponentDescription:desc name:@"HerveNoury:TestCaptureAudioRythm" version:67072]; [AVAudioUnit instantiateWithComponentDescription:desc options:0 completionHandler:^(AVAudioUnit * unit, NSError *error) { self->aUnit = unit; //[self->audioEngine attachNode:self->aUnit]; NSLog(@"AVAudioUnit: %@, error: %@", unit.description, error); }];I added to the info.plist the NSExtension > AudioComponents :<array> <dict> <key>description</key> <string>TestCaptureExtension</string> <key>factoryFunction</key> <string>$(PRODUCT_MODULE_NAME).AudioClass</string> <key>manufacturer</key> <string>rvnr</string> <key>name</key> <string>HerveNoury:TestCaptureAudioRythm</string> <key>sandboxSafe</key> <true/> <key>subtype</key> <string>fltx</string> <key>tags</key> <array> <string>Effects</string> </array> <key>type</key> <string>aufx</string> <key>version</key> <integer>67072</integer> </dict></array>What am I doing wrong that explains that the AVAudioUnit is never instantiated?Thank you in advance for your help.