Using the labs tool ia-upload, it failed to upload a file to Commons with the error being reported being
"The upload to WikimediaCommons failed: Client error response [status code] 413 [reason phrase] Request Entity Too Large [url] https://commons.wikimedia.org/w/api.php?action=upload&filename=Old_and_New_London%2C_vol._1.djvu&format=json"
The file was 57MB in size. I talked to the toollabs developer, and passing on his assessment of why he believed it failed and I was directed to use the standard upload tool. That becomes quite a circuitous route for a file of that size, and it would be great to identify whether the root cause is the API failing or not. thanks.