The cause of this error is due to the Broker Service which integrates Access Capture to the target system (in most cases this is Dimensions)
The Broker Service contains a collection of config files. And it is in the Readsoft Broker Service.exe.config file that contains the user credentials, to connect the Broker Service to the Access Document Management solution.
It is when these user credentials within the config file are invalid, that you will usually see a Document Export Failed error such as Value cannot be null. Parameter name: source
Unless you are an Access Hosted Client, you will be able to resolve this internally by following these steps:
Prerequisites:
Access to the correct server which hosts the Access Readsoft Broker Service
Permissions to stop and start a Windows Service
Permissions to modify files within the directory of the Access Readsoft Broker Service
Once you have the above prerequisites, follow these steps:
On the PC which hosts the Access Readsoft Broker Service locate the service's directory
📌 Note: The Access Readsoft Broker Service is often named this, but can be named Readsoft Broker Service followed by the customername
Open services.msc on the PC and find the service
Right-click the service, then click Properties
Follow the Path to executable for the directory of the Broker Service
On the services' directory open the file Readsoft Broker Service.exe.config.
Search the text in the file for the following value: <ADM>.
This will take you to the correct Node which stores the Access Document Management user credentials.
Update the UserName or Password within the stored credentials fields accordingly.
Save changes to the Readsoft Broker Service.exe.config file.
Stop and start the Broker Service in the services app.
Re-process the export failed document.
Another possible cause is that the password is correct but there have been too many logins to Workspace with that account name and password. It can often happen that the credentials configured for the Capture Broker Service are for an account which someone else is also using for their day-to-day Workspace login. When too many logins have occurred from different IP addresses (any client machine and Capture's broker service server have separate IP addresses) Workspace locks the account and requires the user to manually log in to confirm they are not a robot. As only a 'Human' can do this, the broker service ends up failing to authenticate because it cannot validate it's a Human. To resolve this, log in to Workspace with this account and select the "I'm not a robot" checkbox then log out. Once this is done, re-verify the invoice in Capture.
⚠️ Warning: Any re-verified documents will send a duplicate transaction to the target system.
If Two Factor Authentication is switched on, either for a Workspace Login or for your domain, then Capture users will see the reported error as it can no longer file the image in Access Document. There are three ways to resolve this:
If 2FA has been applied to individual logins then remove it from the above Access Workspace login that capture is using - this is the simplest solution and would require no further changes.
Create a new Access Workspace user account in the normal way without 2FA, assign a Member Role to Access Document and then provide the engineer dealing with the case with the email address and password so that they can update the Capture configuration accordingly.
If 2FA has been applied to the domain then a new Access Workspace user name account must be created, assign a Member Role to Access Document and then provide the engineer dealing with the case with the user name and password so that they can update the Capture configuration accordingly.
It is essential when choosing options 2 or 3, that you can log in to Access Workspace as the new user using only the email address or user name and a password. If Access Workspace requires that you update a temporary password, that must be completed. then log out and log in again until all that is needed to log in is the email address or user name and password.
In the case of solution 2 or 3 a new case will need to be raised with Access as the Capture configuration updates must be made by Access.
If you are an Access Hosted Client, see Get support in Access Capture and quote 'Value cannot be null. Parameter name: source'