The Error: 'The type initializer for 'ABR.AusKeyManager.Keystore.AbrProperties threw an exception' can occur when you attempt to set up the credentials for the first time if accessing HandiTax through Practice Manager.
To resolve please access HandiTax via the HSoft\Apps folder;
Go to the installation path Hsoft\Apps in File Explorer (Help, About in your program will advise location)
Open the executable HTXX.exe (where XX demotes the current year)
Repeat the process to set your credential.
For further assistance, please raise a new case with support online and reference the title of this article.