I recently got a new computer and downloaded Toribash. But I've noticed that most of the mods I loved playing on my old computer simply don't work with my new one. Every time I open a mod it vanishes and text shows up in the mod list saying "_Test2" I try to open that then it switches to the classic mode and red text in the bottom-right corner of my screen says "Unable to open *name of mod i tried to open*/_Test2. How do i solve this problem?

Please post these in "support" board, not general reports sub-board. I'll move it for you this time.

Anyway, it's a known bug in 4.9x, workarounds are:

Alternatively you can not use search bar in mod list (it's what causes the bug) or type only 1 letter max in it. Or alternatively use command /set mod <exactomodname>
You can autofinish mod names by pressing tab.