The parameters in the text were not defined according to the rules

What causes this issue?

The following rules apply for parameter names:
Parameters must be enclosed in '&'.
Parameters must begin with a letter
Only the letters A-Z, a-z, numbers and underscore are allowed as
characters.
A '&' must be coded as a '&&'.
Text is scanned from left to right.

System Response

You cannot save the text.

How to fix this error?

Code the parameters according to these rules.

Error message extract from SAP system. Copyright SAP SE.