PayPal did not receive an acknowledgement form the client application. Therefore, the transaction has not been settled in the account. This issue could be caused by one fo the following reasons: 

• The timeout value is set too low
• The server with the Payflow Pro client is located behind a proxy

Here's how to submit transactions for settlement:

1. Log in to your PayPal Manager account. 
2. Select Virtual Terminal > Multiple Transactions.
3. Select Re-Settle under Transaction Type.
4. Enter the desired Date Range, then click Continue. 
5. Process the transactions as needed.

Note: You can't alter the amount of a transaction in the 106 status. The transaction must be voided and a new transaction issued for the different amount. Here's how to prevent Transaction State 106 from occurring:

• Increase the timeout value
  Verify that the timeout value being sent to the server is 30 seconds or more. If not, try increasing the timeout value.
• Move the server hosting the Payflow Pro client in front of the proxy server
  Check that you're running the most current version of the client (SDK) and move the server in front of the proxy. Perform transactions as normal and compare results to see if the proxy server is causing the problem. 

Payflow Pro
The Payflow Pro client communicates with the Payflow Gateway over a secure TCP/IP-based connection. TCP/IP is called a "connection-oriented" protocol. This always means that both ends of the connection keep track of how they're connected and what data has been sent and received. In addition, the Payflow client does a connectivity check to help ensure that the information is sent and received in the correct order. The Payflow Gateway delivers the results of the transactions to the Payflow client with a Time To Live (TTL), which tells the Payflow Gateway to wait a specific amount of time for an acknowledgement (or ACK). If the Payflow Gateway doesn't receive this confirmation (the ACK), it updates the transaction to a pending state, and the transaction won't be settled.