When initially configuring the ERP Agent for SAP Web AS, the following error may appear in the SAP logs:
"WASUSERNAME is blank or invalid"
The first thing to check is that you have configured a protected realm for the resource in question, and that a user attribute response named "WASUSERNAME" has been set to an appropriate user attribute, such as "uid". If this has been done, you can confirm the front-end Web Agent is adding this response by looking within the Web Agent trace log for the following message:
"Setting custom HTTP header variable: 'wasusername=testuser' from Policy Server"
If you see a message such as this, but the ERP Agent is still not finding WASUSERNAME, check your response attribute name for case-sensitivity. The ERP Agent requires "WASUSERNAME" to be in all capitals; as you can see from the example above, that response was erroneously all lowercase, and will cause the "WASUSERNAME is blank or invalid" message.