SWIFT Sandbox Certificate failure during consuming SWIFT/ API from SWIFT/ SDK application

Faced error during consuming SWIFT Sandbox/ API from Java application leveraging SWIFT/ SDK.
Used SWIFT/ Sandbox Consumer Id and Secret, SWIFT Public-Key Certificate (downloaded using openssl s_connect...).
Error messages as below:
Error from: swift-security-sdk-2.17.6-5-jar-with-dependencies.jar!com.swift.commons.oauth.connection.OAuthConnectionContext.class-

result = {SignatureContextException@4985} Method threw 'com.swift.commons.exceptions.SignatureContextException' exception.
backtrace = {Object[6]@4987}
detailMessage = "Key Storage can't be found by path: https://sandbox.swift.com"
cause = {SignatureContextException@4985} "com.swift.commons.exceptions.SignatureContextException: Key Storage can't be found by path: https://sandbox.swift.com"
backtrace = {Object[6]@4987}
detailMessage = "Key Storage can't be found by path: https://sandbox.swift.com"
cause = {SignatureContextException@4985} "com.swift.commons.exceptions.SignatureContextException: Key Storage can't be found by path: https://sandbox.swift.com"
stackTrace = {StackTraceElement[18]@4989}
depth = 18
suppressedExceptions = {Collections$EmptyList@4990} size = 0
stackTrace = {StackTraceElement[18]@4989}
depth = 18
suppressedExceptions = {Collections$EmptyList@4990} size = 0