Disabling X-FRAME-OPTION: SAMEORIGIN HTTP Response Header on SharePoint/PowerPivot xlsviewer.aspx

This is my understanding of the issue so far:

• sc-win32-status 64 means “The specified network name is no longer available.”
• After IIS has sent the final response to the client, typically it waits for an ACK message from the client.
• Sometimes clients will reset the connection instead of sending the final ACK back to server. This is not a graceful connection close, so IIS logs the “64” code.
• Many clients will reset the connection when they are done with it, to free up the socket instead of leaving it in TIME_WAIT/CLOSE_WAIT.
• Proxies tend to do this more than others do.

Update: I found some interesting information here and here, so I basically re-wrote the page to ensure there wasn't any bad markup etc. and... the problem is now gone! It was just a shot in the dark, and I couldn't definitely say what it was that fixed the problem, since it was only affecting some of our clients under some very specific circumstances...

We had the same problem on one of our test servers which is a single machine installation. In our case the machine was very slow and the crawler tried to crawl too many items at once which results in a timeout.

So we created a crawler impact rule which defines a certain amount of time the crawler waits after each requested item. Such a rule can be created in the Search Settings (in the Central Administration) under "Crawler Impact Rules".

There you can specify the Url for which the rule should be used. Furthermore you have two option to influence the crawler:

• Set the number of items the crawler requests at once
• Set the number of requested item to one and define a certain amount of time, the crawler waits after the request.

So perhaps this might also solve your problem.