mybb forum jump fid=undefined

[networkz]

i have a issue iam using mybb when you go to any section suppose TV section & when you want to jump from TV section to other section from drop down list iam getting error it says in valid forum i've googled did i found similar issues but could not fix

Forum Jump issues - with search engine friendly URLs enabled

but in my case it not /forum--1.html its invalid forum & fid=undefined

thank you