Hey Derkami,
It seems like the "fish" action is not acting properly in the client due to wrongly mapped button.
My current guess is that the categorizing logic for actions/menus under "Adventure" section is slightly messed up.
In fact, "fish" action is being categorized as a menu, and is expecting to open more submenu when you click it.
You can tell this is the case, since the menus and actions are each supposed to be sorted based on alphabet (menu first, actions next), but fishing is placed as a first item.
However, what doesn't make sense is that there is a workaround to this issue.
You can open up a different client (like Ard), add the "fish" action to the shortcut from there, and if you try the shortcut from Kami client, it works (though icon is invisible).
What I assume is happening is that only actions can be put on these shortcuts, and when "fish" action is put there from another client, that info is logged in server side.
Kami client attempts to search the menus list for its icon, but is unable to find it, making it look invisible.
However, when pressed, it sends the action request to the server, and it works normally.
I am suspicious of the MenuGrid.java file's line 400 logic, as it does recursion and checks whether if action has a parent or not.
But I can't tell from a quick look if there is a fault in the logic, and I also don't see why only fishing is handled differently. (possible memory corruption from somewhere?)
I might spend some time later to actually build and debug with some changes, but it's probably much faster for you since you have knowledge on this code already.
TL;DR
to Derkami: Please review MenuGrid.java line 400 or any sort/categorizing mechanism for the bottom right menu buttons. (Maybe GameUI.java, but not sure)
to Others: workaround "fish" bug by using another client (even default one works) and adding "fish" action to the shortcut.