Unable to login to CSM with CSM Client or web page. The "Error at http://csm:1741 is Authentication Failed" on web page and "Login to the server failed. Please enter your username and password again." error messages appear in CSM Client
The error message is received when the login credentials, permissions are not correct or corrupted.
For a workaround,
First check the causer's eligibility for the following policies given below,
Administrative tools > Local security policy > local policies > User Rights Assignment - Access this computer from the network
Administrative tools > Local security policy > local policies > User Rights Assignment > Log on as a batch job
The CSM runs as casuser so the permissions for this user needs to be allowed to access the various DLL files that are required in order for CSM to run. If casuser does not have sufficient permissions to open required DLL files, you receive an access error.
The utility resetcasuser.exe allows you to reset the permissions correctly. You can temporarily add casuser to the Administrators group to see if the errors no longer appear. Since casuser is specifically intended to be the unprivileged account under which CSManager operations run, to make a casuser and administrator is not a solution. This is a good way to test if this is a file permissions problem.
This utility must be run with administrator privileges. This resets the casuser password and modify permissions for the ID that CSM runs as casuser. If you need to reset the privileges for casuser, you can simply run the resetcasuser.exe command from the CLI on the system after you address the interaction with AD in order to reset the user. This is the same program, which originally sets the permissions during installation.
In order to reset Microsoft Windows permissions to default, you can use the Microsoft Local Security Administration tool in order to reapply the MS default security template in C:\WINDOWS\security\templates\setup security.inf.
Note: Permissions problem can also be caused by third party products such as AntiVirus or HostIDS application. Try to disable these in order to see if they are the cause.
If none of these helps, then try to reset the password of the admin account on Cisco Security Manager and run the password reset utility located at C:\Program Files\CSCOpx\bin\resetpasswd.exe.