When I attempt to load up a 1.13 snapshot, it crashes immediately.
When I attempt to load up a current version, like 1.12, an error which reads Unable to create directory. realms-1.10.18.jar can be seen. Mojang, please fix this.

What the Error also had:
Name: realms-1.10.18.jar
URL: https://libraries.minecraft.net/com/mojang/realms/1.10.18/realms-1.10.18.jar
Error details: There is not enough space on the disk
Filename on disk: ca5a-291f-9960-7ec4
Path: C:\Users\Adele\AppData\Local\Temp\ca5a-291f-9960-7ec4
Exists: file