Sorry for the trouble. Let's see if we can get you sorted with the first problem, then we can move unto the next problem.
What kind of Anti-virus software are you running? Sometimes that interferes with the launcher as it falsely flags it.
The Mod Launcher is distributed through a One-Click packaging system. This is a microsoft-based solution, but sometimes it misbehaves.
Let's try to fix that by doing Option A, and if that doesnt work, try option B.
A) Go into Program Files and Remove the 7D2D Mod Launcher, and then re-install it
B) Copy and paste this in an Explorer window: %APPDATA%\..\Local\Apps\2.0 And delete everything in there. This is the OneClick cache that windows maintains for these types of apps. The information will be re-generated when you use a program listed in here
Here's the reference I'm using for the Options:
https://support.microsoft.com/en-us/help/2713442/clickonce-application-fails-to-update