Type constructor threw an exception.(the item was deleted because it was either not found or the crawler was denied access to it
For this error message, foremost, it is a warning and not an error message, sometimes when you receiver this message, it is crawling normally, other times it is because of an issue, like when an item is deleted,
it is perfectly normal to see this in your logs the next time a crawl occurs, this is simply indicating that SharePoint is removing the record from the search index, here are some relative articles about this, please refer to it for more information:
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