Sorry you are having so much trouble with this...you can try the same fix for both products and see if you have better results running our editors afterwards. In Eclipse, go to Window > SlickEdit Preferences > Application Options > Virtual Memory > Spill file path and enter a path. Something like C:\temp\ so that this local path gets used instead of the default value which is probably something under USER_HOME. Sometimes the user home path can have file restrictions, or be on a network drive, etc.
In standalone SlickEdit the option is at Tools > Options > Application Options > Virtual Memory. Let me know if you have better results or if this changes nothing.