Panel Hierarchy Corruption
From X-Plane Wiki
Besides the "flatten" and re-group technique, the other option is:
- Export the entire panel as a text file. Important -- you need to NOT be selecting anything when you export. If there is panel hierarchy corruption, then when you select and export, only part of the selection might be epxorted. But if there is no selection, the export exports _everything_, even instruments that have become invisible due to corruption.
- Then delete all instruments and reimport the panel. Now...where there was hierarchy corruption you may get incorrect grouping. You can solve this in two ways:
1. Simply regroup after the import - once you've imported your panel is fixed and the group commands won't do weird things or
2. Fix the grouping problems by moving the group/endgroup text lines in the text export. If the grouping error causes a huge number of instruments to be mis-grouped, editing the text file might be the quickest way.