Leftover gui_State in GUI made with GUIDE which is called, but does not exist in Object Browser

When running my GUI designed with GUIDE I always encounter the error:

Error using feval
Undefined function 'edit_ap_CreateFcn' for input arguments of type
'matlab.ui.control.UIControl'.

Error in gui_mainfcn (line 95)
        feval(varargin{:});

Error in MMCurveFitting (line 42)
    gui_mainfcn(gui_State, varargin{:});

Error in
@(hObject,eventdata)MMCurveFitting('edit_ap_CreateFcn',hObject,eventdata,guidata(hObject))

The uicontrol edit_ap does not exist anymore (was deleted in GUIDE) and is not visible in the Object Browser. The GUI opens up ok and can be used afterwards without problems, but the error always occurs on startup. How can I get rid of the leftover remains from older GUI pieces? It seems to me like the fig is corrupted to some extent (On the same note I use Matlab R2015a on Mac which seems to have problems with displacing GUI controls over the surface).

Thanks in advance! Felix

[Felix Baeuerle]

So, I "solved" the problem by making a new uicontrol with the tag edit_ap, saved and ran everything (no errors) and then deleted it again (no more errors).