OAuth 2.0 refresh tokens that are required for connecting to QuickBooks Online expire with time (see Devart.Data.QuickBooks.QuickBooksConnectionStringBuilder.RefreshToken). While they may live for 100 days in theory, sometimes data source may revoke it after just one day. dotConnect for QuickBooks Online can automatically store them between application sessions and obtain new ones when necessary if this parameter is set.
Refresh tokens can be stored either in a file or in the registry. Here are examples of values for these parameters:
"Token Server=file://D:\\temp\\oauth_token_1234.txt" "Token Server=reg://HKEY_CURRENT_USER\\Software\\Devart\\dotConnect\\OAuth_12345"
Note that it is required to add either "file://" or "reg://" to the beginning of the parameter value to specify whether tokens will be stored in a file or in a registry key.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2