I installed the latest Image show as a result of various errors and issues and now image show config references gk_coffe and is causing the module to throw more errors
mod_image_show_gk4.xml line 52 is as follows ...
<field name="module_style" type="styles" default="gk_coffe" label="MOD_IMAGE_SHOW_GK4_MODSTYLE" />
change this to your specific template may help some issues but create style issues to be fixed.