1) Move the client folder directly to drive C:/ (C:/Stellaria)
2) Turn off antivirus or add the game folder to exceptions

To fix this, you need to download and install
.NET Framework - DOWNLOAD
1) Download the installation file from the link
2) Install .NET Framework and restart your computer

To fix this, you need to download and install add-ons from the following links:

DirectX - DOWNLOAD
1) Download the installation service for DirectX module
2) Install DirectX and restart your computer

Visual C++ Redistributable Runtimes - DOWNLOAD
1) Download the archive
2) Extract it to your desktop
3) Run the install_all.bat file as administrator

This error can be easily fixed as follows:
1) Open the userdata folder in the client
2) In this folder (userdata) create a new folder named messages

If the login won't let you into the game (outside of maintenance), please check your time settings.
1) Turn on automatic time setting
2) Turn on automatic daylight saving time adjustment

If your client crashes after selecting a character or the screen gets stuck while loading, reinstall the client:
1) Delete the entire client folder
2) Download the client again from our website
After downloading, extract the ENTIRE Stellaria folder to your desktop.
Then open this folder on your desktop and run the Stellaria-launcher file
The game will update and be fully functional.