If you followed the Sage 50 US Pre-installation & Connection Guide we asked you to create a specific user for the Sync Tool with either Administrator or Full Access to Sage 50 US.
A problem that this could create for you is that it's possible to sync invoices into a closed period in Sage 50, since the User created has privileges to do so.
You can prevent this this from occurring by adjusting the access the User set up in the sync tool.
Log into Sage 50 US as the Admin and go to Maintain -> Users -> Set Up Security
Select the user which is being used by the Sync Tool and select Edit User's Rights.
Change the selection to Selected Access and press Next.
In the following screen go to Company and scroll to the Task section. Here change the setting Transactions in Prior Periods to View Only and Save.
This will prevent the user set up in the tool from posting transactions into a closed period in Sage 50 US.
One very important note: When you're preforming a sync with Sage 50 US you must be logged in Sage 50 as this user. If you're logged in as another user with different access, it's possible that user's privileges will override the privileges of the user in the sync tool.
For example if you're logged into Sage 50 US as the Admin when you preform a sync, the Admin privileges supersedes that of the user in our tool. Therefor the transaction could still post into the closed period.
If all is set up correctly you should see the following sync error when a invoice attempts to sync into a closed period.
The invoice itself in SageAPA will Sync Error, you'll need to Reset the invoice and change the date & due date before you can export and sync again.