Hi JKA,
Unfortunately, you discovered a bug a in CardExchange. If the value mapped to a contactless item is of the type Decimal, the Mifare module throws this exception. We are currently in the testing phase of a new release and this bug fix will be included. The new release is expected for September the 5th.
In the meanwhile, I have the following work around for you: Please, map the contactless item that gives the trouble not directly to the database column, but choose the option Concatenation field. Then map the first sub node of the concatenation to the database column. By using the concatenation field mapping, you force CardExchange to convert the decimal value to a string before sending it to the contactless item. With this construction the problem should not occur.
regards,
Rutger.
Rutger Koperdraad
Senior Software Engineer
"A reasonable man adapts himself to the world. The unreasonable man persists in trying to adapt the world to himself. All progress, therefore, depends on the unreasonable man." (Bernard Shaw)