The Outline client for Windows uses Microsoft Visual C++ Redistributable x86 libraries for its work. If they are not installed on the computer, the program may keep «crushing» because of the «unexpected error».
To fix this problem, install Microsoft Visual C++ Redistributable x86 libraries. You may download them:
following the direct link https://aka.ms/vs/17/release/vc_redist.x86.exe;
from the libraries repository on the Microsoft website.
N.B.: when downloading the libraries from the Microsoft website, choose an x86 version, even if you have x64-bit operating system.
When the installation is over, restart your computer and launch Outline once again.