Maybe you're seeing this problem? (just a guess, without knowing the actual errors or seeing your screen)
https://forum.pjrc.com/threads/54608-Teensyduino-ide-installation-issue
If that's what's happening, the solution is simple: just select anything in the Tools > Ports menu. Doesn't matter what you select, even something that's not a board at all (eg, if your computer has bluetooth, it might appear in that menu). Then restart Arduino. This bug is triggered only when nothing has ever been selected. (prior versions of Arduino always had a default - recently it changed)
Or you could install
this beta which has the bug fixed. But if you can select something in the Ports menu, you're probably better off using the stable 1.45 rather than the 1.46 beta.