<p>One of the methods is to transfer all the data to newly created .ai file, sometimes it happens to solve a problem...</p>
<p>Second one is to reset preferences in your Adobe Illustrator, but now always this method works, especially with serious corruptions, more likely way is Illustrator Restore Toolbox - it has free demo, with the feature of restoring of some corrupted files without acquiring full version on <a href="https://www.restoretools.com/illustratorrestore.html">https://www.restoretools.com/illustratorrestore.html</a></p>
