Do not use f:repeatable use f:repeatableProperty instead

[gbhat618]

#535 (comment)

This is a low-level form control which regular plugins should never touch. I think you wanted to use f:repeatableProperty.

It needs fixing here

google-compute-engine-plugin/src/main/resources/com/google/jenkins/plugins/computeengine/ComputeEngineCloud/config.jelly

Lines 35 to 40 in 0a3fb1b

	<f:entry title="${%Instance Configurations}"
	description="${%List of instance configurations that can be launched as Jenkins agents}">
	<f:repeatable field="configurations">
	<st:include page="config.jelly" class="${descriptor.clazz}"/>
	</f:repeatable>
	</f:entry>

For reference see the custom metadata feature in this plugin - uses f:repeatableProperty