There doesn’t seem to be any known issues for 7.23.5 and exporting to excel.
I just gave it a go locally on an app and it seemed to work fine.
Try doing the normal troubleshooting things like restarting the app, clearing cache, checking security (even though you can see it on the frontend, could be something else).
The error seemed to come from some data points not having entered data for specific attributes, once i deleted these i was able to export without system errors.