How To Fix TD620 - Error calling the program for processing format '&'

SAP Error Message - Details

• Message type: E = Error

• Message class: TD - SAPscript: Text editor, composer, forms, styles and fonts

• Message number: 620

• Message text: Error calling the program for processing format '&'

What causes this issue?

The text format specified requires that an external word processor is
called. An error occurred when this word processor was called.
Possible reasons for this exception can be:

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

The external word processor is not installed or is incorrectly installed
on the frontend.
The word processor could not be started.
An error occurred during communication with the word processor.
An error occurred during transmission of the text data.
...

System Response

The required function is not executed.

How to fix this error?

SAPscript forwards the text module to appropriate function modules
which set up the connection to the respective word processing program.
These function modules return the exception COMMUNICATION which states
that an error occurred when this word processing program was called.
For information on the error which has occurred, please refer to
the documentation on the function modules:
EDIT_TEXT_FORMAT_xxx
PRINT_TEXT_FORMAT_xxx
CHECK_TEXT_FORMAT
xxx stands for the format specified above.
The word processing program called sometimes also displays an error
message. If this is the case, you should also refer to the
documentation on this word processor for appropriate measures to
correct the error which has occurred.

Error message extract from SAP system. Copyright SAP SE.