I get an error message when I try to ring up a sale "XML Render - Compiler error token "xxx" was not found."

You have edited the receipt footer and inserted a phrase without quotes.
Example: You entered Visit us on the web at.... when you should have entered "Visit us on the web at...".
If you leave out quotes the receipt format routine is trying to lookup the variable entered. Valid variables would be something like Store.Name. The word Visit is not.

Resolution: Go to Manager | Database | Registers | Receipt Formats and select the offending format. Edit the Properties (Sales) and select the Footer Line number affected. Insert quotation marks at the beginning and end of the phrase. Exit and save, then restart the POS program.

TIP: Click the Refresh button and view your changes in the right panel. Double-click on the image to zoom in.