title: Delphi: GridPanelLayout ColumnCollection error
body: <p>I'm working on a simple (Delphi 10.1, FireMonkey) application that includes a GridPanelLayout component, 2 rows, 5 columns, each cell has a TGlyph component. The last thing I did yesterday was adjust the margins for both the GridPanelLayout and Glyphs. Everything seemed OK; I compiled and ran on Windows and OS X. I honestly can't remember whether I tried the app on Android or not at that point! In any case, I saved everything, committed to Git, and called it a day.</p>
  
  <p>This morning, opening the same project I got</p>
  
  <blockquote>
    <p>Error reading GridPanelLayout1.ColumnCollection: Cannot delete a
    column that contains controls. Ignore the error and continue? NOTE:
    Ignoring the error may cause components to be deleted or property
    values to be lost.</p>
  </blockquote>
  
  <p>Clicking "Ignore All" generates </p>
  
  <blockquote>
    <p>Error creating form: Stream read error.</p>
  </blockquote>
  
  <p>If I click OK, the app compiles and runs fine on Windows. </p>
  
  <p>The same process on Mac OS X, however, generates </p>
  
  <blockquote>
    <p>Exception EReadError in module ... Error reading
    GridPanelLayout1.ColumnCollection: Cannot delete a column that
    contains controls.</p>
  </blockquote>
  
  <p>I can't trying compiling the app for Android right now, but a google search led me to try simply switching the view to <code>Style: Android</code>, <code>View: Android 5" Phone</code>, generating the error</p>
  
  <blockquote>
    <p>View "LgXhdpiPh" already exists in module.</p>
  </blockquote>
  
  <p>Switching the view to <code>Style: OSX</code>, <code>View: OS X Desktop</code> generates</p>
  
  <blockquote>
    <p>View "Macintosh" already exists in module.</p>
  </blockquote>
  
  <p>And I checked the form's dfm code (i.e., Alt-F12); I see the the same 5 columns, 2 rows, and Glyphs assigned to cells as expected.</p>
  
  <p>Any idea what's going on?</p>