We have tested the sorting in Sitefinity 6.3, we selected "Last Modified on Top
" and there wasn't any problem. Could you please send us a screenshot of the error that you are getting and your Error.log file located in App_Data -> Sitefinity -> Logs (clear them, reproduce the problem and send them to us).
Regarding the first problem with sorting Taxonomies by Last Modified on Top, the bug has been fixed for Sitefinity 7.0. You could upgrade your project following our upgrade documentation
and the problem will not be encountered.
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