You need more details than that (writing a bug report). Game crashes get technical so we need technical details.
The most common reasons for a crash, if you aren't getting the Warframe Crash reporter, is some kind of GPU driver fault. If you have update your GPU drivers lately try uninstall and downgrading to the last version you know worked.
Need more details before you can get serious help. Starting with platform you are playing on, please include "distribution store" if on PC. Hardwired ethernet or WiFi? Solo or Squad play?
You will not get much help with such sparse information. So much could be going wrong.
Please write a bit more in your bug report (how to). Like Platform. Graphics Card type. CPU type (and model). Operating System. If Windows PC, distribution platform (Standalone/Steam/Epic).
Like most vague tech support rants with zero information, this doesn't help Reddit fix anything, because there's:
If people are going to leave vague feedback about something, they should at least use some sort of form or you know, the text box to provide someone some sort of information.
This post and others like it are the digital equivalent of someone calling tech support and saying "Something is wrong with my computer, come fix it." then hanging up.
Note how other people giving legitimate feedback are responded to and actioned by admins