Unable to access card reader

What causes this issue?

The system cannot access the card reader for one of the following
reasons:
The card reader is switched off.
The profile for the card reader was not installed correctly in the
<GL:Secure_Store_and_Forward>SSF</> information about the user.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

RESET N1
Depending on what caused the error, proceed as follows:
Switch on the card reader.
Ask your system administrator to correct the SSF information about your
user (see Customizing for <LS>Basis Components</>, section <LS>System
Administration</> -> <LS>Administration of External Security
Systems</>).
After the SSF information has been changed, call the dialog box for the
digital signature again,
Execute your signature.

Error message extract from SAP system. Copyright SAP SE.