There is no sha256 sum in http://download.jboss.org/jbosstools/mars/staging/builds/jbosstools-4.3.0.CR1a-build-browsersim-standalone/latest/
So no sha was copied to http://download.jboss.org/jbosstools/static/mars/development/updates/core/jbosstools-4.3.0.CR1-browsersim-standalone.zip.sha256

I've manually created the files, but we need to know why it's not being created automatically as part of the build, eg., in http://download.jboss.org/jbosstools/mars/snapshots/builds/jbosstools-browsersim-standalone_4.3.mars/latest/ or http://download.jboss.org/jbosstools/mars/snapshots/builds/jbosstools-browsersim-standalone_master/latest/