# Resolving an Empty Fingerprint Issue

Given the following situation: You call the GetInfo method in Sentinel Licensing API to fetch the fingerprint for an SL UserMode key. The fingerprint that is retrieved resembles the following:

    <?xml version="1.0" encoding="UTF-8" ?>
    <hasp_info>
       <host_fingerprint type="SL-UserMode" vendorid="37515"
       crc="3820837874">NHhJSQ==</host_fingerprint>
    </hasp_info>

This indicates that the API method retrieved an empty fingerprint. This occurs when the SL UserMode license cannot be accessed or is corrupted.

The most common reason for this issue is that access to the directory that contains the SL UserMode licenses is denied. When you resolve the access permission issue, the API method will be able to fetch the fingerprint as required.

If the problem is not caused by access permissions, the most likely cause is that the SL UserMode licenses have become corrupted.

To resolve this issue, you must clear the entire SL UserMode license directory. As a result, all locked licenses will be invalidated due to clone protection. It will be necessary to reissue these licenses.

Unlocked licenses can be reinstalled in the directory.

For information on the location of SL UserMode licenses on the user’s machine, see “Viewing License Updates” in the Sentinel LDK Software Protection and Licensing Guide.

## Related Topics

Scope Input XML Tags