Chef is not able to read the secrets from databag

Hi , chef is unable to read the data from the databag and in the logs of /opt/chef/cache/chef-stacktrace.out it is showing below error but we don't changed any key .

Chef::Exceptions::RunFailedWrappingError: Found 1 errors, they are stored in the backtrace
1) Chef::EncryptedDataBagItem::DecryptionFailure - Error decrypting data bag value: ''. Most likely the provided key is incorrect.

Below is the error log from chef=client.log
Failed to read the private key /etc/chef/validation.pem: #<Errno::ENOENT: No such file or directory @ rb_sysopen - /etc/chef/validation.pem>



^[[31mChef encountered an error attempting to create the client "^[[0m


^[[0mPrivate Key Not Found:^[[0m


Your private key could not be loaded. If the key file exists, ensure that it is

Can someone help me on this?