Port-channel between 9500 and 4500-x

[k.aumell]

- devices: C9500 (stackwise) and C4500 (VSS)

- trying to build port-channel but getting the following errors:

*Nov 9 15:40:04.795: %PM-4-ERR_DISABLE: channel-misconfig error detected on Te1/1/7, putting Te1/1/7 in err-disable state

*Nov 9 15:40:06.191: %LINK-3-UPDOWN: Interface TenGigabitEthernet1/1/7, changed state to down

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C9500 virtual stackwise
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interface Port-channel126
description link to 4500x
switchport mode trunk

interface TenGigabitEthernet1/1/7
switchport mode trunk
channel-group 126 mode active

interface TenGigabitEthernet1/1/8
switchport mode trunk
channel-group 126 mode active

interface TenGigabitEthernet2/1/7
switchport mode trunk
channel-group 126 mode active

interface TenGigabitEthernet2/1/8
switchport mode trunk
channel-group 126 mode active

----------------------------------
4500-x VSS
----------------------------------

interface Port-channel254
description Port-Channel to 9500-Distro
switchport
switchport mode trunk

interface TenGigabitEthernet1/1/25
description Port-Channel to 9500-Distro
switchport mode trunk
channel-group 254 mode active

interface TenGigabitEthernet1/1/26
description Port-Channel to 9500-Distro
switchport mode trunk
channel-group 254 mode active

interface TenGigabitEthernet2/1/25
description Port-Channel to 9500-Distro
switchport mode trunk
channel-group 254 mode active

interface TenGigabitEthernet2/1/26
description Port-Channel to 9500-Distro
switchport mode trunk
channel-group 254 mode active

Doesn't seem all that complicated. I do have Dual-active-detection link on 9500. 4500-x side does not go into error disable.

Its been days exchanging email with TAC, so any help is appreciated.

9500 show run attached

[marce1000]

 - Configure a syslog server (the same) on both devices , then configure logging trap debugging , try to make the link again , check the logs send to the syslog server.

 M.