Error: Expected a Resource or Concept

When I try to execute the transaction in composer-playground I got an error "getAssetRegistry is returning null and the error message says assetRegistry is not defined"

/*Here is my .cto file: */

 namespace org.acme.payrent
  participant Authority identified by authorityId  {
      o String authorityId
  }

participant Tenant identified by tenantEmailId {
  o String tenantEmailId regex =/^([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5})$/
  o String tFirstName
  o Address Address
  o TBankDetails tBank
  o Integer accountNo 
}

participant Owner identified by ownerEmailId {
  o String ownerEmailId regex =/^([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5})$/
  o String name
  o String number regex=/^[0-9]*$/
  o Integer bankaccountno
  o Address propAddress
  --> Tenant tnt
}

participant Bank identified by bankID {
  o String bankID
  o TBankDetails tBank
}

asset Property identified by propAddress {
  o String propAddress
  o Address propActAddress
  o String tenantName
  o Double rentAmount
}

 concept Address {
  o String houseNumber
  o String street
  o String city 
  o String country
}

concept TBankDetails {
  o String bankName
  o String ifscCode
  o String branchName
}

concept Contact {
  o String email regex =/^([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5})$/
  o String mobileNumber regex=/^[0-9]*$/
  o String firstName
  o String lastName
}

event E1{
o String email
o String mobileNumber regex=/^[0-9]*$/
o String tntName
o TBankDetails tntBankDetails
o Address propertyAddress
}

transaction Agreement{
  --> Property property
  o String owrName
  o String tntName
  o String email
  o String propAddress
  o String mobileNumber
  o String bankName
  o String ifscCode
  o String branchName
}`

/* chaincode/logic.js file: */ ` /** * Place an order for a vehicle * @param {org.acme.payrent.Agreement} the Create Agreement transaction * @transaction */

function Agreement(tntObj)
{
  debugger
    var factory = getFactory(tntObj);
    var Namespace = "org.acme.payrent";
    var property = tntObj.propAddress;
    var addTntEvent = factory.newEvent(Namespace, 'E1');
    addTntEvent.email = tntObj.email;
    addTntEvent.mobileNumber  = tntObj.mobileNumber ;
    addTntEvent.tntName = tntObj.tntName;
    addTntEvent.tntBankName = tntObj.bankName;
    addTntEvent.ifscCode = tntObj.ifscCode;
    addTntEvent.branchName = tntObj.branchName;
    var a = getAssetRegistry('org.acme.payrent.Property');
    return getAssetRegistry('org.acme.payrent.Property')
                            .then(function(propertyRegistry){
                                return assetRegistry.update(property); });
}`

Access control file:permission.acl
`/**
 * New access control file
 */
rule Default {
    description: "Allow all participants access to all resources"
    participant: "ANY"
    operation: ALL
    resource: "org.acme.payrent.*"
    action: ALLOW
}

rule SystemACL {
  description:  "System ACL to permit all access"
  participant: "ANY"
  operation: ALL
  resource: "org.hyperledger.composer.system.**"
  action: ALLOW
}

rule Owner {
     description: "Owner can add a Tenant"
     participant: "org.hyperledger.composer.system.Participant"
     operation: ALL
     resource: "org.hyperledger.composer.system.**"
     action: ALLOW
 }

 rule Bank {
     description: "Bank can verify tenant's bank account"
     participant: "org.hyperledger.composer.system.Participant"
     operation: ALL
     resource: "org.hyperledger.composer.system.**"
     action: ALLOW
 }

 rule Govenment {
     description: "To verify property belongs to owner"
     participant: "org.hyperledger.composer.system.Participant"
     operation: ALL
     resource: "org.hyperledger.composer.system.**"
     action: ALLOW
 }`

there are a number of issues with your code

the original issue of expected Resource or Concept was the latter - this wasn't being supplied correctly to the Event
you were using the wrong object when assigning to property so your assetRegistry update would not work
you need to define the Concept values when you assign to your event fields - see code
have left in console.logs so you can see the output
you need to provide more data (eg, Concept Address fields) to your transaction
there is a rentAmount assignment below - you need to remove - its there so you can see that the Property Asset has been updated as it should be by the transaction Agreement


/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Sample transaction processor function.
 * @param {org.acme.payrent.Agreement} tntObj The sample transaction instance.
 * @transaction
 */

function Agreement(tntObj)
{

    var factory = getFactory();
    var Namespace = "org.acme.payrent";
    var property = tntObj.property;   // please note
    console.log('property is ' + property);
    var addTntEvent = factory.newEvent(Namespace, 'E1');
    addTntEvent.email = tntObj.email;

    addTntEvent.mobileNumber  = tntObj.mobileNumber ;
    addTntEvent.tntName = tntObj.tntName;

    var tntBankDetails = factory.newConcept(Namespace, 'TBankDetails');

    tntBankDetails.bankName = tntObj.bankName;
    tntBankDetails.ifscCode = tntObj.ifscCode;
    tntBankDetails.branchName = tntObj.branchName;

    addTntEvent.tntBankDetails = tntBankDetails;

    var conceptAddress = factory.newConcept(Namespace, 'Address');

    conceptAddress.houseNumber = '10';
    conceptAddress.street = '20';
    conceptAddress.city = 'Mainz';
    conceptAddress.country = 'DE';

    addTntEvent.propertyAddress = conceptAddress;

    emit(addTntEvent);



    //remove this! var a = getAssetRegistry('org.acme.payrent.Property');

    property.rentAmount =44.22 ; /// so you can see the value change on the asset in playground etc

    return getAssetRegistry('org.acme.payrent.Property')
                            .then(function(propertyRegistry) {
                                return propertyRegistry.update(property); 
    });
}