xlsx validation app?

Hi folks,

I generate some xlsx files from a xojo made app.
the base xlsx file has been updated, and I get a file that excel cannot open.
is there some xlsx validation tool that exists around to narrow the search for the xml error ?


edit: found this one but there is nothing to run ? : https://archive.codeplex.com/?p=ooxmlvalidator

for the records, I found this microsoft tool : https://www.microsoft.com/en-us/download/details.aspx?id=5124
there is an SDK, and a tool to open office documents, and tell you where is a potential error.
user interface is … well … crude, but it does the job and let me find my mistake !