I found out that if I was to right click on the application in my taskbar and close the engine, I could not open it again
I'm afraid I can't duplicate this issue with my system. Are you using 0980e? What Windows version is it? The need of downloading again the installer is completely nonsensical to me. If the installer you have from a previous download doesn't work, I can think right now of few reasons, first one that involve damaged files is a hard disk issue, and I'd check for errors with some disk tool. Second one, a rootkit virus.
Provided that your system is in good shape, it could be helpful if you attach your
se.log file, it's in your
SpaceEngine/system/ folder, actually two, one collected when the program is working and visible, one from when it shows that issue.
Instead of reinstalling the whole thing: if you are using 0980e patch, try to replicate the issue without installing the patch and see if it works. If you're not using the patch, or it shows the issue no matter what, delete the file
main-user.cfg you find in
SpaceEngine/config/ folder, delete files and subfolders in
cache/ folder.
As for the skybox issue, check if it shows again with patch 0980e not installed.
SDL2.dll Was not found fix? why is this happening
Maybe because you're using only the 0980e patch, not the main 0980 space engine installer. Download SpaceEngine executable installer from the download webpage, install it, then you can apply the patch, as described in that page.
If this is not the case, could you please attach your
se.log file which is located in your
SpaceEngine/system/ folder, as requested in the first post of this thread?