Not able to download file with `Customer-managed-encryption`

I have a bucket with CMEK enabled on it(Default encryption set to customer managed key). When trying to `cp` the file from Bucket to local it
`gsutil cp gs://source_data_in_blr/output/dir_output.tsv/_SUCCESS .`

fails with following error :

`AccessDeniedException: 403 We're sorry, but the Customer-Supplied Encryption Key feature is not available in your location; see https://cloud.google.com/storage/docs/encryption/customer-supplied-keys#restrictions for more details.`

output of : `gcloud config list`

```
[compute]
region = us-east1
zone = us-east1-b
[core]
account = xxxxx@xxxxxx.com
disable_usage_reporting = True
project = xxxxxx
``````

Version details:

``````
gsutil version: 4.38
checksum: 58d3e78c61e7e0e80813a6ebc26085f6 (OK)
boto version: 2.49.0
python version: 2.7.10 (default, Feb 22 2019, 21:55:15) [GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.37.14)]
OS: Darwin 18.6.0
multiprocessing available: True
using cloud sdk: True
pass cloud sdk credentials to gsutil: True
config path(s): /Users/kadarsh/.boto, /Users/kadarsh/.config/gcloud/legacy_credentials/kadarsh@thoughtworks.com/.boto
gsutil path: /usr/local/google-cloud-sdk/bin/gsutil
compiled crcmod: True
installed via package manager: False
editable install: False
```