App Crashed when open screen Only

[Anke]

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How to get rid of this error message "no method named Column in class edu.mit.appinventor"

export aia open it with 7-Zip or winRAR go to the affected ScreenX.scm: right mouse click: “Edit” (or: F4) remove “Column”:“X” and “Row”:“Y” close Editor & 7-Zip / winRAR No need to copy or rename anything. See the solution from @Svetlana_GREGOIRE : Newbie here...need a little help invoke: no method named `Column' in class edu.mit.appinventor