Oops, downloading failed

Community Help
1

I’m attempting to “Download PNG” for a chart I’ve made via Vega-Lite-API, but I’m getting a little red error on top: “Oops, downloading failed.”

“Download SVG” works.

No errors in console. Running Safari on Mac. I’ve been able to do this in the past.

Any ideas?

2

Perhaps a CORS issue. Can you share the link to your notebook, or alternatively provide a reduced example in which the problem can be reproduced?

3

I will try to make a reduced example.

Really weirdly, though, in Safari I selected “Disable Cross-Origin Restrictions” and then I was logged out of Observablehq.com and could not log back in. Deselecting returned things to normal.

4

Perhaps related?

[Error] Error while parsing the 'sandbox' attribute: 'allow-downloads' is an invalid sandbox flag.
	Mt (index-6c673751.js:7:20381)
	lu (index-6c673751.js:7:90434)
	Ec (index-6c673751.js:7:110536)
	Cc (index-6c673751.js:7:110425)
	bc (index-6c673751.js:7:110278)
	sc (index-6c673751.js:7:107354)
	sc
	(anonymous function) (index-6c673751.js:7:58949)
	(anonymous function) (index-6c673751.js:7:11615)
	ra (index-6c673751.js:7:58895)
	na (index-6c673751.js:7:58830)
	ic (index-6c673751.js:7:104137)
	enqueueSetState (index-6c673751.js:7:62618)
	(anonymous function) (index-6c673751.js:7:2336)
	(anonymous function) (notebook-97fb35b4.js:2:564887)
	asyncFunctionResume
	(anonymous function)
	promiseReactionJobWithoutPromise
	promiseReactionJob

The cell render is SVG, so presumably that’s why SVG works and PNG (which perhaps needs to actually be downloaded) doesn’t?

5

That shouldn’t matter, because the worker iframe doesn’t initiate a download. Instead, the parent frame (i.e., the editor UI) requests a rendered PNG blob of the cell contents from the worker via postMessage (you can search for request_download to find both the initiator and handler).