unknown object in stream 9

This exception is equivalent to unknown object in stream SymmetricKeyEncrypted. Usually occurs when we try to decrypt a conventionally OpenPGP encrypted file (also known as password encrypted or PBE) that was created with PGP 2.x or McAfee E-Business Server 7.x.

This issue has been addressed in OpenPGP Library for Java version 2.5.6 and upper and OpenPGP Library for .NET 1.7.1 and upper versions. Please update your version in order to resolve this issue.