Error – Command rejected: An interface whose trunk encapsulation is “Auto” can not be configured to “trunk” mode

switch(config-if)#switchport mode trunk
Command rejected: An interface whose trunk encapsulation is “Auto” can not be configured to “trunk” mode.

This is a result of a missing encapsulation command type (That is 802.1Q on that port). Follow the steps below to fix this “Command Rejected” error message.
– Enter the interface configuration mode and enter the following command below

switch(config-if)#switchport trunk encapsulation dot1q

Before proceeding with the rest configuration
– You can now set the port as a trunk without any issue.

switch(config-if)switchport mode trunk

For other guides, see: How to clear Cache and Manually Update Microsoft Defender, How to fix: This network connection does not exist and Reveal the WiFi password of the Network you are connected to in Windows.

I hope you found this blog post on fixing this “Command Rejected” error helpful. If you have any questions, please let me know in the comment session