Why do I get InvalidPackageDirectory error during validation and deployment tasks?

Stage: Validation, Deployment Build Task: Deploy a Source Directory (Source Format) to an Org

sfpowerscripts... Deploy Source to Org
Converting source to mdapi
Converting to MDAPI Format force-app in project directory
ERROR running force:source:convert:  InvalidPackageDirectory
Unable to convert source for directory force-app
##[error]Command failed: npx sfdx force:source:convert -r force-app  -d QTcO4_mdapi
ERROR running force:source:convert:  InvalidPackageDirectory

Possible Resolution: Check that all your defined packages in sfdx-project.json has at least 1 file in the package directory so that the sfdx cli detects that the package exists and is valid. During the mdapi conversion process, it will reference the sfdx-project.json file before starting to convert the specified package.

Why am I getting a SyntaxError:Unexpected token exception when I use any of these commands?

Check that all your defined packages in sfdx-project.json have these following attributes defined

package:<name-of-the-package> // this is mandatory for each of the packages
versionNumber:<X.Y.Z.BuildNumber/NEXT> //this is mandatory for each of the packages
versionName:<any-version_name>