Dataflow Refresh Error with SharePoint

Hi,

I've had a data flow that is connected to a Sharepoint csv for months without issue and now I'm getting the following error when refreshing the data:

"SharePoint: Request failed: The underlying connection was closed: An unexpected error occurred on a send."

I've tried clearing the permissions and reconnected but end up with the same error.

I've also tried uninstalling and reinstalling Power Bi desktop.

The file is not large (5 mb) and I am able to navigate my SharePoint library from within Power Bi.

[EDIT]

Upon further investigation, I found that it succesfully located my CSV file on SharePoint but then fails when retrieving the binary content with a slightly different error message:

"DataSource.Error: The underlying connection was closed: An unexpected error occurred on a send."

[EDIT 2.0]

I have managed to extract a more detailed error message:

Unexpected error: The underlying connection was closed: An unexpected error occurred on a send.
Details:

Microsoft.Mashup.Evaluator.Interface.ErrorException: The underlying connection was closed: An unexpected error occurred on a send. ---> Microsoft.Mashup.Evaluator.Interface.ErrorException: The underlying connection was closed: An unexpected error occurred on a send. ---> Microsoft.Mashup.Evaluator.Interface.ErrorException: The underlying connection was closed: An unexpected error occurred on a send. ---> Microsoft.Mashup.Evaluator.Interface.ErrorException: The underlying connection was closed: An unexpected error occurred on a send. ---> Microsoft.Mashup.Evaluator.Interface.ErrorException: The underlying connection was closed: An unexpected error occurred on a send. ---> Microsoft.Mashup.Engine1.Library.Http.ResponseException: The underlying connection was closed: An unexpected error occurred on a send. ---> Microsoft.Mashup.Engine1.Library.Http.ResponseException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
--- End of inner exception stack trace ---

at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.FixedSizeReader.ReadPacket(Byte[] buffer, Int32 offset, Int32 count)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest, Boolean renegotiation)
at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.PooledStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.ConnectStream.WriteHeaders(Boolean async)
--- End of inner exception stack trace ---