Hi, I got the same error, but I found a way to get it to work...
What I do is before I create the widget that is going into the Workspace I create a dummy one. I'm guessing that the bug is due to some initialization that is not been done on the first Workspace created, here is the dummy dialog... main_window_ptr = omui.MQtUtil.mainWindow() mayaWid = QtCompat.wrapInstance(long(main_window_ptr), QtWidgets.QWidget) class dummyClass(MayaQWidgetDockableMixin, QtWidgets.QDialog): def __init__(self, parent=None): QtWidgets.QDialog.__init__(self, parent) _dummyUI = dummyClass(mayaWid) _dummyUI.setObjectName("DockingDummyWindow") workspaceControlName = _dummyUI.objectName() + 'WorkspaceControl' _dummyUI.show(dockable=True, area='right', floating=False) cmds.workspaceControl(workspaceControlName, e=True, ttc=["AttributeEditor", -1], wp="preferred", mw=420) cmds.workspaceControl(workspaceControlName, e=True, close=True) cmds.deleteUI(workspaceControlName, control=True) Once this is deleted, you add the code that creates the real UI. It works for me, so maybe try it out. Cheers, -- You received this message because you are subscribed to the Google Groups "Python Programming for Autodesk Maya" group. To unsubscribe from this group and stop receiving emails from it, send an email to python_inside_maya+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/python_inside_maya/a0c45475-217e-46a0-94c2-29c1fa0b257a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.