Webpanel/homepage fails to open in my browser.

Hello, everybody,

I want to open the LuCI webpanel/homepage link in my browser for reaching the settings of my Arduino Yun.

If I write the IP address of my Yun in my browser, I got this message:

?:0: attempt to index a nil value
stack traceback:
?: in function ‘read_gpg_pub_key’
?: in function <?:144>
?: in function ‘dispatch’
?: in function <?:194>

Else If I write IP address of my Yun/cgi-bin/luci in my browser, the link does work well.
I fill in the fields of username and password.

Then, I click on ‘Arduino Web Panel’. After, I click on ‘Configure’ and I see this message:

Failed to execute call dispatcher target for entry ‘/webpanel/config’.
The called action terminated with an exception:
?:0: attempt to index a nil value
stack traceback:

: in function 'assert'
	?: in function 'dispatch'
	?: in function <?:194>

Thank you for your understandings.

Update your firmware?