My app crash but i dont know why, no method named Column

[Taifun]

this seems to be a bug in App Inventor...
as workaround did you try the solution by @Svetlana_GREGOIRE ?

Newbie here...need a little help invoke: no method named `Column' in class edu.mit.appinventor

Hello, I have the same problem and i fix it. 1.export the bad project 2 create a copy 3. rename your bad project to a *.zip and open the zip, open src/appinventor… to the end. you have 2 files, if you have one screen (Screen1.scm and Screen1.bky) extract Screen1.scm and open it with notepad++ 4. there is a line code in the beginning like that : {“authURL”:[“ai2.appinventor.mit.edu”],“YaVersion”:“205”,“Source”:“Form”,“Properties”:{"$Name":“Screen1”,"$Type":“Form”,"$Version":“27”,“AppName”…

Taifun