problem editing pipelines created using azure-devops extension

Wen creating a pipeline using the az pipelines create command, the pipeline works fine, but if I edit it in the Azure DevOps web interface (yaml editor), i get this error consistently


If I from te web interface delete the pipeline and recreate it (still in the the web ui) pointing to the same repo/yaml file, it works fine it will work again, and now the editor will also show the yaml file without problems.

I had
**Version information:**
I had the same problem on azure-cli 2.0.79 with devops 0.16.0 - updating did not help. Here is current version information:

azure-cli 2.6.0
command-modules-nspkg 2.0.3
core 2.6.0
nspkg 3.0.4
telemetry 1.0.4

Extensions:
azure-devops 0.18.0

Python location 'C:\Program Files (x86)\Microsoft SDKs\Azure\CLI2\python.exe'
Extensions directory 'C:\Users\anrem\.azure\cliextensions'

Python (Windows) 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 02:47:15) [MSC v.1900 32 bit (Intel)]

**Command to create te pipeline:**
az pipelines create --name $serviceName --description 'Pipeline for $serviceName' --org https://dev.azure.com// --project $ProjectName --repository $serviceName --branch master --repository-type tfsgit --yml-path azure-pipelines.yml