bad argument #1 to 'pairs'

bad argument #1 to 'pairs'

/usr/lib/lua/luci/dispatcher.lua:566: bad argument #1 to 'pairs' (table expected, got nil)
stack traceback:
	[C]: in function 'pairs'
	/usr/lib/lua/luci/dispatcher.lua:566: in function 'createtree'
	/usr/lib/lua/luci/dispatcher.lua:226: in function 'dispatch'
	/usr/lib/lua/luci/dispatcher.lua:147: in function </usr/lib/lua/luci/dispatcher.lua:146>

root@ACU:~# ls -alh /tmp/luci-indexcache 
-rw-------    1 root     root       99.0K Nov  2 16:47 /tmp/luci-indexcache
root@ACU:~# 
root@ACU:~# rm /tmp/luci-indexcache 
root@ACU:~# 
root@ACU:~# curl -IL 'http://localhost:8000'
HTTP/1.1 200 OK
Connection: Keep-Alive
Keep-Alive: timeout=20
ETag: "bac-1ef-5f9ab1e7"
Last-Modified: Thu, 29 Oct 2020 12:13:27 GMT
Date: Mon, 02 Nov 2020 08:49:40 GMT
Content-Type: text/html
Content-Length: 495

root@ACU:~# 

============= End