How can I use protected hds on AMS(Version: 5_0_6_9003 AMI Version: r1)?

I suddenly could not use protected hds.

There are some errors on apache logs.

[Wed May 13 16:19:10 2015] [info] Error while creating DRMAdditionalHeader.

[Wed May 13 16:19:10 2015] [error] mod_f4fhttp [500]: An invalid certificate was passed to DME

Could you please tell me how to fix the above error?

Should I update the following certificates?

creds/static/phds_license_server.der

creds/static/phds_production_transport.der

creds/static/phds_license_server.pfx

creds/static/phds_production_packager.pfx

creds/static/phds_data

Thanks.