When you try to create a new bucket using the s3 service the program is unable to detect if it already exists because _.detect method is deprecated in lodash 4.0.0 and on, resulting in the following error:

Running "s3:build" (s3) task
##vso[task.debug]load strings from: F:\Desarrollo\vewd-app-base\node_modules\vsts-task-lib\lib.json
##vso[task.debug]load loc strings from: F:\Desarrollo\vewd-app-base\node_modules\vsts-task-lib\Strings\resources.resjson\en-US\resources.resjson
##vso[task.debug]task result: Failed
##vso[task.complete result=Failed;]Unhandled: _.detect is not a function
Unhandled: _.detect is not a function

It needs to be replaced with _.find method for it to work.

More info here https://github.com/lodash/lodash/wiki/Deprecations

Cheers.