Spark 2.2 in Windows does not recognize the URI "file:Z:\SIT1\TreatmentManager\app.properties"

We are currently running Spark 2.1 in Windows Server 2012 in Production. While trying to upgrade to Spark 2.2.0 spark we started getting this error after submitting job in stand-alone cluster mode:

Could not load properties; nested exception is java.io.IOException: java.net.URISyntaxException: Illegal character in opaque part at index 7: file:Z:\SIT1\TreatmentManager\app.properties

We passing a -D argument to the spark submit with a value of file:Z:\SIT1\TreatmentManager\app.properties

These URI -D arguments was working fine in Spark 2.1.0

UPDATE: I replaced the \ with / and it works.