A Windows NT 4 and Windows 2000 error that occurs when more than 4096 files have been encrypted on the system. This is the full error message:

1381L ERROR_TOO_MANY_SECRETS The maximum number of secrets that can be stored in a single system was exceeded. The length and number of secrets is limited to satisfy the United States State Department export restrictions.

Yet another wonderful case of the ever-helpful US government restricting the rights of users world-wide. In order to circumvent this, you need to have the domestic high encryption patch for Windows, which allows you to have more than 4096 encrypted files on the system.