The error message usually indicates the XML cannot be parsed correctly. If you are not familiar with XML, then note that the symbols are very important. Also, your screenshot shows the sysProps.xml also has an error of some kind. Below is what the build.xml file should look like.
<?xml version="1.0" encoding="UTF-8"?>
<project name="FRC Deployment" default="deploy">
<!--
The following properties can be defined to override system level
settings. These should not be touched unless you know what you're
doing. The primary use is to override the wpilib version when
working with older robots that can't compile with the latest
libraries.
-->
<!-- By default the system version of WPI is used -->
<!-- <property name="version" value=""/> -->
<!-- By default the system team number is used -->
<!-- <property name="team-number" value=""/> -->
<!-- By default the target is set to 10.TE.AM.2 -->
<!-- <property name="target" value=""/> -->
<property file="${user.home}/wpilib/wpilib.properties"/>
<property file="build.properties"/>
<property file="${user.home}/wpilib/cpp/${version}/ant/build.properties"/>
<import file="${wpilib.ant.dir}/build.xml"/>
</project>