The Report Entity Ticket Symbol/Name must be written without spaces or special characters in lower case letters. This is because this name will be used as file name, when extensions are created and these cannot have special characters.
This error will be raised if any of the following special characters are used:
- :
-
?
-
*
-
|
-
\
-
/
-
<
-
>
To fix this, open the ESEF report settings and remove any special characters from the Report Entity Ticket Symbol/Name field: