Few problems with search
2-How to switch this two sections?(move up search results)
3.How to change this "recent posts" breadcrumb pharase?
1. This comes from your current active theme, To make sure just switch to some other theme and check again.
2. I'm sorry, but there is no any option for this purpose.
3. All wpForo front-end phrases are located in Dashboard > Forums > Phrases admin page, just find it, and change as you like.
1. yes when theme change it issue gone. but I cant change theme.
can you help for this?
3. I change but not change.
There should bee some option in your theme settings to disable this function. This is a JS Plugin in theme which finds all drop-down menus and changes them. Just ask this question to the theme developers and they'll explain how to disable it for certain page or totally.
In any case if you don't find solution you can use this CSS code. Just put it in Dashboard > Forums > Settings > Custom CSS Code textarea. Save it, delete all caches, navigate to forum front-end and press Ctrl+F5.
Just search for "Recently Added" phrase in Dashboard > Forums > Phrases admin page, edit and change to whatever you want. If you don't find this phrase, click on [Add new], insert "Recently Added" as phrase key and your phrase as phrase value.