# Mess USB descriptor has errors

**URL:** <https://backstage.polyend.com/t/mess-usb-descriptor-has-errors/24386>\
**Category:** Mess\
**Created:** [March 21, 2026, 3:52pm UTC](https://backstage.polyend.com/t/mess-usb-descriptor-has-errors/24386 "2026-03-21T15:52:38Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![ark](https://backstage.polyend.com/user_avatar/backstage.polyend.com/ark/32/240_2.png) [@ark](https://backstage.polyend.com/u/ark)\
**Post date:** [March 21, 2026, 3:52pm UTC](https://backstage.polyend.com/t/mess-usb-descriptor-has-errors/24386/1 "2026-03-21T15:52:38Z")

</div>

[Thesycon.de](http://thesycon.de/) has a little tool called tdd.exe that reports the details of a device’s USB descriptor on Windows. When I run that tool on a Polyend Mess, it reports errors in the descriptor. Here is its output:

Information for device Mess (VID=0x16D0 PID=0x111C):

\*\*\* ERROR: Descriptor has errors! \*\*\*

* * *

## Connection Information:

Device current bus speed: HighSpeed  
Device supports USB 1.1 specification  
Device supports USB 2.0 specification  
Device address: 0x002A  
Current configuration value: 0x01  
Number of open pipes: 2

* * *

## Device Descriptor:

0x12 bLength  
0x01 bDescriptorType  
0x0200 bcdUSB  
0xEF bDeviceClass (Miscellaneous device)  
0x02 bDeviceSubClass  
0x01 bDeviceProtocol  
0x40 bMaxPacketSize0 (64 bytes)  
0x16D0 idVendor  
0x111C idProduct  
0x0101 bcdDevice  
0x01 iManufacturer “Polyend”  
0x02 iProduct “Mess”  
0x00 iSerialNumber  
0x01 bNumConfigurations

Device Qualifier Descriptor is not available. Error code: 0x0000001F

* * *

## Configuration Descriptor:

0x09 bLength  
0x02 bDescriptorType  
0x0053 wTotalLength (83 bytes)  
0x01 bNumInterfaces  
0x01 bConfigurationValue  
0x00 iConfiguration  
0x80 bmAttributes (Bus-powered Device)  
0x32 bMaxPower (100 mA)

## Interface Descriptor:

0x09 bLength  
0x04 bDescriptorType  
0x00 bInterfaceNumber  
0x00 bAlternateSetting  
0x02 bNumEndPoints  
0x01 bInterfaceClass (Audio Device Class)  
0x03 bInterfaceSubClass (MIDI Streaming Interface)  
0x00 bInterfaceProtocol (Audio Protocol undefined)  
0x00 iInterface

## MS Interface Header Descriptor:

0x07 bLength  
0x24 bDescriptorType  
0x01 bDescriptorSubtype  
0x0001 bcdMSC  
0x0025 wTotalLength (37 bytes)

## MS MIDI IN Jack Descriptor:

0x06 bLength  
0x24 bDescriptorType  
0x02 bDescriptorSubtype  
0x01 bJackType  
0x01 bJackID  
0x00 iJack

## MS MIDI IN Jack Descriptor:

0x06 bLength  
0x24 bDescriptorType  
0x02 bDescriptorSubtype  
0x02 bJackType  
0x02 bJackID  
0x00 iJack

## MS MIDI OUT Jack Descriptor:

0x09 bLength  
0x24 bDescriptorType  
0x03 bDescriptorSubtype  
0x01 bJackType  
0x03 bJackID  
0x01 bNrInputPins  
0x02 baSourceID(1)  
0x01 baSourcePin(1)  
0x00 iJack

## MS MIDI OUT Jack Descriptor:

0x09 bLength  
0x24 bDescriptorType  
0x03 bDescriptorSubtype  
0x02 bJackType  
0x04 bJackID  
0x01 bNrInputPins  
0x01 baSourceID(1)  
0x01 baSourcePin(1)  
0x00 iJack

## Endpoint Descriptor (Audio/MIDI 1.0):

0x09 bLength  
0x05 bDescriptorType  
0x01 bEndpointAddress (OUT endpoint 1)  
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)  
0x0040 wMaxPacketSize (64 bytes)  
0x00 bInterval  
0x00 bRefresh  
0x00 bSynchAddress  
\*\*\* ERROR: Invalid wMaxPacketSize. Must be 512 bytes in high speed mode.

## MS Bulk Data Endpoint Descriptor:

0x05 bLength  
0x25 bDescriptorType  
0x01 bDescriptorSubtype  
0x01 bNumEmbMIDIJack  
0x01 baAssocJackID(1)

## Endpoint Descriptor (Audio/MIDI 1.0):

0x09 bLength  
0x05 bDescriptorType  
0x81 bEndpointAddress (IN endpoint 1)  
0x02 bmAttributes (Transfer: Bulk / Synch: None / Usage: Data)  
0x0040 wMaxPacketSize (64 bytes)  
0x00 bInterval  
0x00 bRefresh  
0x00 bSynchAddress  
\*\*\* ERROR: Invalid wMaxPacketSize. Must be 512 bytes in high speed mode.

## MS Bulk Data Endpoint Descriptor:

0x05 bLength  
0x25 bDescriptorType  
0x01 bDescriptorSubtype  
0x01 bNumEmbMIDIJack  
0x03 baAssocJackID(1)

Microsoft OS Descriptor is not available. Error code: 0x0000001F

* * *

## String Descriptor Table

Index LANGID String  
0x00 0x0000 0x0409  
0x01 0x0409 “Polyend”  
0x02 0x0409 “Mess”

* * *

Connection path for device:  
USB xHCI Compliant Host Controller  
Root Hub  
Mess (VID=0x16D0 PID=0x111C) Port: 1

Running on: Windows 10 or greater (Build Version 26200)

Brought to you by TDD v2.19.0, Dec 5 2023, 12:08:38