Unrecognized selector while getting au.mainApp().getTreeForXML()


I am quite new to Appium testing and have now a problem, where I cannot continue because of a crash, when I am trying to get any element by name:

Debug: evaluating au.mainApp().getTreeForXML()
-[UICollectionReusableView accessibilityClearInternalData]: unrecognized selector sent to instance 0x7f6…

How does the selector “accessibilityClearInternalData” come into the UI tree? Haven’t found anything in my code. After googling the selector, I have only found something in the class “UICollectionViewCellAccessibility”, but this has nothing to do with UICollectionReusableView.

Thank you in advance.