Did you move the Cache within Windows by drag/drop or move/Paste? If so, you should not do that. On the Premiere Edit Menu go to Preferences and the Media tab. There you will find the means to move the Cache to where you want it, and Premiere will be able to find it.
Normally Premiere simply re-creates the cache in the default location if it is opened, and the location it expects to find the cache is inaccessible.