Hi,
I'm on the evaluation, I have a Kinect 2.
After running Evaluate Background and moving to the Record tab, on pressing Start Recording it always crashes with this,

iPi Recorder 4.0.6.66

OS: Microsoft Windows NT 10.0.17134.0 (64 bits)
.NET: 4.7.2.461808
CPU count: 8
GC: workstation (Interactive)
Running in 64 bits

System.InvalidOperationException: Sequence contains no elements
at System.Linq.Enumerable.Max[TSource](IEnumerable`1 source)
at #=zvcQFbhiNPej6MVas9_TOd5Y=.#=zlEsuflyBo4acUFLb7LtlppQrcXCzym0NhkWNZJE=(Boolean #=z2yMReccDtPhdqeBKkQ==, Int64& #=zkB4cp_oXJR$B, Boolean #=zAil_bycmldHn4x10X3aTXCo=)
at #=zvcQFbhiNPej6MVas9_TOd5Y=.#=zqq6gvYQovUKG(Boolean #=z2yMReccDtPhdqeBKkQ==, Boolean #=zAil_bycmldHn4x10X3aTXCo=)
at iPiRecorder.Recorder.ViewModel.RecordStageViewModel.<StartRecordingAsync>d__122.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at iPiRecorder.Recorder.ViewModel.RecorderViewModel.<ExecuteStartRecording>d__121.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

If it makes any difference I initially tried to connect both a Kinect 1 and 2 but was told by IpI Record they were not compatible. I then uninstalled the Kinect 1 drivers and SDK and rebooted and only have the Kinect 2 connected now - it is working fine as seen in Kinect Studio.
Since then I've also completely reinstalled the recorder but always get the same error.

Hi
Thanks for reporting.
The issue has been introduced in the latest release of iPi Recorder 4.0.6. We'll make a fix in a few hours. In the meanwhile you can downgrade to previous release 4.0.5.
Sorry for inconvenience.

Release v4.0.7.67 fixes this issue.