Unable to read the e2ee_private_key file '%1'. The error code is %2

Error code 255
Error constant E2EE_READING_PRIVATE_KEY
Parameter 1 The private key file from the e2ee_private_key option.
Parameter 2 The error code.
Probable cause

An error occurred reading the e2ee_private_key file. Please contact technical support and provide the error code.