I can't reproduce this (I did an FB login here, and could get to the Edit tab fine.
Please see if you can get a JavaScript stack trace for this error. Modern browsers (if the JS console stays open) will usually let you expand the error and see a trace.
Also see if you can find anything in Composr's error log (data_custom/errorlog.php), and any errors shown coming in in the browser's Network requests from an AJAX script.
Please see if you can get a JavaScript stack trace for this error. Modern browsers (if the JS console stays open) will usually let you expand the error and see a trace.
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I inspected Composr's errorlog.php file, there is nothing there.
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