WSO2 ESB error on deploying gmail mediator - wso2

Question

I'm following the wso2 gmail connector tutorial here but getting the error,
ERROR - MediatorFactoryFinder Unknown mediator referenced by configuration element : {http://ws.apache.org/ns/synapse}gmail
I followed all the steps mentioned, got my gmail credentials and configured the mediators in the sequence.
What am I missing?
The xml,
<?xml version="1.0" encoding="UTF-8"?>
<sequence name="PaymentRequestProcessingSequence" trace="disable" xmlns="http://ws.apache.org/ns/synapse">
<property description="Get Email ID" expression="json-eval($.patient.email)" name="email_id" scope="default" type="STRING"/>
<call>
<endpoint key="SettlePaymentEP"/>
</call>
<log description="LogPaymentRequestProcessingSequenceRes" level="full">
<property name="type" value="LogPaymentRequestProcessingSequenceRes"/>
<property expression="get-property("INTERNALREQUESTID")" name="internalrequestID"/>
<property expression="get-property("MessageID")" name="messageID"/>
<property expression="." name="message"/>
</log>
<property description="Get Payment Response" expression="json-eval($.)" name="payment_response" scope="default" type="STRING"/>
<gmail.init>
<userId>myEmail</userId>
<accessToken>theAccessToken</accessToken>
<apiUrl>https://www.googleapis.com/gmail</apiUrl>
<clientId>theClientId</clientId>
<clientSecret>theClientSecret</clientSecret>
<refreshToken>theRefreshToken</refreshToken>
</gmail.init>
<gmail.sendMail>
<to>{$ctx:email_id}</to>
<subject>Payment Status</subject>
<messageBody>{$ctx:payment_response}</messageBody>
</gmail.sendMail>
<drop/>
</sequence>
Stacktrace
ERROR {org.apache.synapse.deployers.LibraryArtifactDeployer} - Deployment of synapse artifact failed for synapse libray at : C:\Program Files\WSO2\Enterprise Integrator\6.4.0\tmp\carbonapps\-1234\1546859692950SampeServicesCompositeApplication_1.0.0.car\gmail-connector_3.0.7\gmail-connector-3.0.7.zip : Error while extracting Synapse Library : gmail-connector-3.0.7.zip {org.apache.synapse.deployers.LibraryArtifactDeployer}
org.apache.synapse.SynapseException: Error while extracting Synapse Library : gmail-connector-3.0.7.zip
at org.apache.synapse.libraries.util.LibDeployerUtils.extractSynapseLib(LibDeployerUtils.java:426)
at org.apache.synapse.libraries.util.LibDeployerUtils.createSynapseLibrary(LibDeployerUtils.java:65)
at org.apache.synapse.deployers.LibraryArtifactDeployer.deploy(LibraryArtifactDeployer.java:60)
at org.wso2.carbon.application.deployer.synapse.SynapseAppDeployer.deploySynapseLibrary(SynapseAppDeployer.java:355)
at org.wso2.carbon.application.deployer.synapse.SynapseAppDeployer.deployArtifacts(SynapseAppDeployer.java:101)
at org.wso2.carbon.application.deployer.internal.ApplicationManager.deployCarbonApp(ApplicationManager.java:272)
at org.wso2.carbon.application.deployer.CappAxis2Deployer.deploy(CappAxis2Deployer.java:72)
at org.apache.axis2.deployment.repository.util.DeploymentFileData.deploy(DeploymentFileData.java:136)
at org.apache.axis2.deployment.DeploymentEngine.doDeploy(DeploymentEngine.java:807)
at org.apache.axis2.deployment.repository.util.WSInfoList.update(WSInfoList.java:144)
at org.apache.axis2.deployment.RepositoryListener.update(RepositoryListener.java:377)
at org.apache.axis2.deployment.RepositoryListener.checkServices(RepositoryListener.java:254)
at org.apache.axis2.deployment.RepositoryListener.startListener(RepositoryListener.java:371)
at org.apache.axis2.deployment.scheduler.SchedulerTask.checkRepository(SchedulerTask.java:59)
at org.apache.axis2.deployment.scheduler.SchedulerTask.run(SchedulerTask.java:67)
at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.runAxisDeployment(CarbonDeploymentSchedulerTask.java:93)
at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.run(CarbonDeploymentSchedulerTask.java:138)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.io.FileNotFoundException: C:\Program%20Files\WSO2\Enterprise%20Integrator\6.4.0\tmp\carbonapps\-1234\1546859692950SampeServicesCompositeApplication_1.0.0.car\gmail-connector_3.0.7\gmail-connector-3.0.7.zip (The system cannot find the path specified)
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(Unknown Source)
at java.util.zip.ZipFile.<init>(Unknown Source)
at java.util.zip.ZipFile.<init>(Unknown Source)
at org.apache.synapse.libraries.util.LibDeployerUtils.extract(LibDeployerUtils.java:448)
at org.apache.synapse.libraries.util.LibDeployerUtils.extractSynapseLib(LibDeployerUtils.java:424)
... 23 more