Data Transfer Error Message in Dues Management

Dear FreeToastHost Support Team,
I received the error message below while editing the custom message in Dues Management, Invoice Settings.
Up to this point I had been editing and previewing successfully but now the Custom Message seems to be gone as well as Your Information.
Possibly, I inadvertently deleted a } in a double }} and tried to preview.
i have cleared cookies and updated website from server several times; no change, and I keep getting the error message. How do I clear this error message and get my Custom Message and Information back?
My browser is Firefox and it is up-to-date.
Thank you for your assistance.

***DATA TRANSFER ERROR***
JavaScript Function=DuesTool[GetDuesMgtJSON]
Status=error
Error=

Please notify us about this at support.toastmastersclubs.org .

do you know which variable your delete the } from?

Possibly {{Member}} or {{tres}}

Try it now.

Perfect! Thank you!