Server crash while trying to invoke a gui class

MC: 1.11.2
Mod Version: 1.0.3

This is a server-side only problem. The "Project Table" has been saved in the "EZ Storage2" device, which calls the "getStackDisplayName" method to recive the ItemStack name. This causes the ItemPlan class to invoke a gui class, which is of course not available on the server-side.

Crash-Report: https://gist.github.com/DerOli82/4b6173117225dfed14f22957a6948d2c