HMGR0149E appears in the node agent HPEL or SystemOut.log.
HMGR0149E: An attempt to open a connection to core group DefaultCoreGroup has been rejected. The sending process has a name of your_cell\your_node\dmgr and an IP address of x.x.x.x. Global security in the local process is Enabled. Global security in the sending process is Enabled. The received token starts with ??????^[^K?<?P?.?)^X^Y-??DQ. The exception is com.ibm.websphere.security.auth.WSLoginFailedException: Validation of LTPA token failed due to invalid key or token type.
I experienced this event after adding a self-signed certificate to the node default keystore. The name of my self-signed certificate was "testing".
This caused the status of the node and the application servers in the node to be unknown (question mark icon) in the dmgr.
To resolve this, I did the following.