Launcher crashes when i try to open it

I have the same issue, here is the tail of my launcher's log :

[Error: 2020-06-05 15:22:21.8588262: MinecraftServicesApi.cpp(90)] Error while sending request to [https://api.minecraftservices.com/authentication/login_with_xbox]
{{ [Error: 2020-06-05 15:22:21.8588508: MinecraftServicesApi.cpp(93)] https://api.minecraftservices.com/authentication/login_with_xbox responded with: Response code: 401 Response body:}}{{{ "path" : "/authentication/login_with_xbox", "errorType" : "UnauthorizedOperationException", "error" : "UnauthorizedOperationException", "errorMessage" : "Unauthorized", "developerMessage" : "Unauthorized", "details" :
{ }}}{{}}}

I had the same issue and found a possible solution. It seems to be an xbox live login token issue, getting a wrong one from cache (maybe you changed to beta release usage and this might caused it, this is when happened to me). 

Try to disconnect your internet, start Minecraft Dungeons Launcher, wait until it complains about no internet, click on your username on the top left corner and Sign Out, then close launcher (maybe even clear out beta in Settings before). Reconnect your internet and start Launcher and login normally.

I disconnected my internet like Janos said, and it worked, I got in, I didn't even have to log out or anything

Could anyone please attach the launcher_log.txt file from %AppData%\.minecraft_dungeons after getting this issue?

A fix for the issue that was causing the Launcher to crash on that scenario is now available in the latest Dungeons Launcher version (2.1.15376).

i figured out how to fix it. open it directly. open the file location using the shortcut and open the original file