Structured Data Linter choked on page it used to handle

[The Bicycling Guitarist]

Greetings from The Bicycling Guitarist.

I recently added many itemid and sameAs metadata to my page  Thoughts on Seversky's book Victory Through Air Power that already had 1500 microdata statements before I added more.

The structured data linter now chokes when I enter the html code as direct input and tries to tell me there is no structured data detected. However the Google SDTT and the Yandex microdata tool both still extract a LOT of structured data from both the page url and the direct input of its html code

Maybe I'm tired and doing something wrong, or maybe it's my machine or my connection. I tested more than once, cleared cookies and tried again. Did this page just now cross some magic barrier too big for the linter tool to handle? It's not that big a file really even if I did go a little overboard on the markup (partly to see and learn how much can be marked up on a page). Obviously I'm still learning. Any insights from people who know more about this than I do? Is the file size the problem? Number of statements? Number of itemid pointing to wikipedia links supported by dbpedia and wikidata sameAs links? The w3c unicorn validator says the html5 code is valid. Google and Yandex can still read it. What happened with the Structured Data Linter tool? or am I wrong?