Forum Discussion

Copper Contributor

Sep 10, 2020

SharePoint CSOM - Unable to read data from the transport connection: An existing connection

While doing some not heavy operations (like add admins, add content type) in SharePoint CSOM we are getting below error which is not reproducible but comes intermittently. Mainly different article po...

PnP

susiew32

Copper Contributor

Update your .net framework version to at least 4.7.2. This will enable TLS 1.2 which is necessary for the data transfer.

DonHeuvelman

Copper Contributor

Jun 16, 2021

I have an application running .NET 4.8 which is showing the same behavoir.
I'm extracting files from SharePoint per iteration. It runs for about 10 iterations, then I get the same exception as mentioned.

dscore
Copper Contributor
Aug 18, 2021
DonHeuvelman, did you ever get a solution?
- DonHeuvelman
  Copper Contributor
  Aug 19, 2021
  dscore Yeah, sort of, we put the whole request in a loop and append a sleep to it.
  So we can request multiple times at once, about 10 or 11. Whenever a following request fails with the given exception, you have to wait until the previous connection is closed and this takes a few seconds, we just wait in the thread and continu after a few seconds (we try again until it succeeds)
  Elegant? Not at all.. but its sufficient enough for our goals. (if it looks stupid but it works.... it's not stupid .. well not really but you get the point 😉 )
JasonEades
Copper Contributor
Aug 18, 2021
DonHeuvelman Do you get the problem if you slow the process down? Maybe put some sleep operations in at the end of each iteration. If not TLS related, perhaps SP is throttling you?