Error when deploying Fiori app from VS code -Unexpected token '<', "<!DOCTYPE "... is not valid JSO

[TRN1]

Hi Experts,

I am trying to deploy SAP UI5 Fiori application from VS code to ABAP on-premise system. I installed all the extensions needed in VS code to create a Fiori application and was able to preview the application in the local host. When it comes to deployment to the backend system, I get the below error when running the command 'npm run deploy' and deployment fails.  

error abap-deploy-task ZDFGT Deployment has failed.
error abap-deploy-task ZDFGT Change logging level to debug your issue
error abap-deploy-task ZDFGT (see examples https://github.com/SAP/open-ux-tools/tree/main/packages/deploy-tooling#configuration-with-logging-en...)
error builder:custom deploy-to-abap Unexpected token '<', "<!DOCTYPE "... is not valid JSON
Command deploy failed with error : Unexpected token '<', "<!DOCTYPE "... is not valid JSON

Any suggestions to resolve this error please?

Thank you for your help in advance!

[Dinu]

The error '<', "<!DOCTYPE "... is not valid JSON has high probability of being an authentication issue. The ABAP system is responding with HTML, possibly for signing in to the request to deploy. 

[TRN1]

Initially I got the certificate error. Then, I used "ignoreCertError: true" in the UI5-deploy.yaml file and got rid of the certification error.