Resolution:
Description:
============
When starting the Hawk agent from the command line, the following error is seen:

***
[Fatal Error] :35:91: An invalid XML character (Unicode: 0x0) was found in the element content of the document.
org.xml.sax.SAXParseException: An invalid XML character (Unicode: 0x0) was found in the element content of the document.
…
***

Environment:
===========
Linux systems.
Hawk 4.9.0.

Cause:
=====
The error message may be caused by a problematic rulebase.

Resolution:
==========
Check the Hawk.log file to see if you can find error messages resembling the following:

***
Corrupt rulebase XXX from <tra>/domain/<DOMAIN>/rulebase/XXX.hrb, name of the rulebase does not correspond to the name of the file.
***

Unload/remove the “Corrupt rulebase” and restart the Hawk agent.