i same error. temporal solution: stop server, delete data image library and guishop plugin and start server.                  posible bug new version guishop i investigation. 

Its seeking a diffrent path then where the server is installed then locks serverstartup i had to remove it to be able to start the server.
This happened since the last guishop update.

I run the old GUIShop on my other servers the one with the new guishop has this issue

exact same issue

I have opened a post in guishop please post it there to give visibility and the author repairs it. thx
https://umod.org/community/gui-shop/34104-guishop-does-not-allow-the-server-to-start

Alright, so this issue occurs when another plugin tries to call it by doing ( //requires + does it either inside Loaded() or Init() ) before the server has booted. To fix this the plugin causing the problem needs to move their LoadImages(); method into oxides OnServerInitialized.