Build failure for react app preview: No such property: uri for class: SimpleTemplateScript

Preview builds for the membership portal have been failing since around a month ago. The logs show the following message:

hudson.remoting.ProxyException: groovy.lang.MissingPropertyException: No such property: uri for class: SimpleTemplateScript93

Take a look at a full log here: https://foundation.eclipse.org/ci/webdev/job/public/job/membership.eclipse.org/job/MR-643/3/console

Seems to be present in all MRs for the react app. I haven't noticed this anywhere else.

It seems to have happened around March 10th judging from the build history in this MR. No commits have been pushed to the MR in that time period.

@heurtemattes @mbarbero

Please take a look!