assume that your microflow run java action RunMicroflowAsyncInQueue right ?, This java action need a microflow to run async , is it null ? or any of entity in the miroflow use audit trail super class ?
Your error log shows that there was a problem running task #3 due to an invalid value for the parent class. This may indicate a bug in the code that requires the parent class to not be empty. You probably need to check what data is being passed to this task to ensure that incorrect values are not being passed in.