AWS SAM Deploy error - Validation Error | CreateChangeSet Operation Error - amazon-web-services

Question

I get the following error upon attempting to sam deploy --guided my lambda application.
Error: Failed to create changeset for the stack: {stack-name}, An error occurred (ValidationError) when calling the CreateChangeSet operation: Stack:arn:aws:cloudformation:ap-southeast-2:014009325916:stack/{stack-name}/f2212bf0-bb41-11ea-8ef3-0aa7af0536b6 is in ROLLBACK_COMPLETE state and can not be updated.
Some further context into this issue is that all of my lambda functions do not have authorization defined. Not sure if that is related but I'm stating it in the case that it is.
I frankly have no idea how to go about this issue. Any help is appreciated.
===
Context: Building an automated trading system
Request for Cloudformation Template:
yaml
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A tradingview alert wrapper that interprets alerts and makes trades according to them.
Globals:
Function:
# CodeUri: function/.
# Runtime: python3.8
# Policies:
# - AWSLambdaFullAccess
# Tracing: Active
# Timeout: 30
Environment:
Variables:
APIKEY: ""
SECRETKEY: ""
Resources:
tradeFunction:
Type: AWS::Serverless::Function
Properties:
Handler: app.trade
Description: The primary execution function
CodeUri: function/.
Runtime: python3.8
Policies:
- AWSLambdaFullAccess
Tracing: Active
Timeout: 60
Events:
inputResponse:
Type: Api
Auth:
ApiKeyRequired: false
Authorizer: NONE
Properties:
Path: /trade
Method: post
printAccountBalanceFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: function/.
Runtime: python3.8
Policies:
- AWSLambdaFullAccess
Tracing: Active
Timeout: 30
Handler: app.print_account_balance
Description: Returns account balance over time or trade
Events:
inputResponse:
Type: Api
Properties:
Path: /print_account_balance
Method: get
startTradesFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: function/.
Runtime: python3.8
Policies:
- AWSLambdaFullAccess
Tracing: Active
Timeout: 30
Handler: app.start_trades
Description: Resets trade log for a fresh start
Events:
inputResponse:
Type: Api
Properties:
Path: /start_trades
Method: get
retrieveTradeLogFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: function/.
Runtime: python3.8
Policies:
- AWSLambdaFullAccess
Tracing: Active
Timeout: 30
Handler: app.retrieve_trade_log
Description: Return all the trade logs in the dyanamoDB database
Events:
inputResponse:
Type: Api
Properties:
Path: /retrieve_trade_log
Method: get

Answer 1

The error is encountered to my understanding when one does an initial deployment and that initial deployment fails. As a result of this, something breaks and the deployment service can not execute successfully. To fix this issue, simple delete the aws cloudformation stack and redeploy.
One can use the following command to delete:
aws cloudformation delete-stack --stack-name <insert stack-name>
Reference

Answer 2

Might need to run sam build first so your resources can get the latest changes