draw.io "Page could not be loaded. Please try refreshing."

[tlaerm]

On starting a draw.io grain it loads for few seconds an then displays "Page could not be loaded. Please try refreshing." message in the grains area. This is browser independent. The JS console shows:

https://039e762ea7738ef1fdb8aad96a0ded2b.mydomain.sandcats.io:6080/js/app.min.js Failed to load resource: net::ERR_CONTENT_LENGTH_MISMATCH
039e762ea7738ef1fdb8aad96a0ded2b.mydomain.sandcats.io/:340 Uncaught ReferenceError: EditorUi is not defined

Trying to load the app.min.js gives an empty file.

It did work once and I did some diagramming so I'm really stumped on this. Any ideas? Would be really grateful for any pointers.

[kentonv]

This is pretty strange. Is your Sandstorm server behind any kind of proxy?

Does this happen for all draw.io grains (including new ones) or only a specific grain?

[ghost]

Hi, have same problem.
This happens because whole app is "minificated" in app.min.js and its too heavy (3.9mb) and js file got failed to load after ~6 sec

[ghost]

@kentonv I'm using clean vagrant installed version. If you want to check it, don't forget to set connection type in chrome dev tools, 3G is enough to emulate this error, trying find out difference between your demo page where all working fine, and my vagrant installed version.

[tlaerm]

Hi Kenton, hi Artjom, thanks for looking into this.
My install is not behind a proxy and running on a fairly powerful bare metal machine. Don't think that's an issue. @artjoms-faltins is probably onto something. I've tested and it happens consistently on a slow connection I have to use sometimes. This is a 6 Mbit DSL link. Works on a 50 Mbit link.

[kentonv]

Indeed I can reproduce this. The download dies after ~33 seconds, only having downloaded 3.1MB of the 3.9MB file. But I'm not sure why it would stop. Sandstorm does not impose any timeout here. Maybe Chrome imposes a 30s limit on Javascript?

@davidjgraph, have you run into this before?

[davidjgraph]

We've never heard of this one outside of Sandstorm. ERR_CONTENT_LENGTH_MISMATCH, I think is usually a mis-behaving proxy, http://stackoverflow.com/questions/23521839/failed-to-load-resource-neterr-content-length-mismatch, but given rdd2 doesn't have one and that we haven't released a new draw recently, could there be a server issue delivering large files?

We certainly could split up the app into 3-4 parts, but 3.9MB shouldn't be causing trouble (is there wire compression?) and we might just be masking a deeper issue.

[ghost]

@kentonv First I think so but, if you will go to demo service https://oasis.sandstorm.io and try to open draw.io project, you will succeed without any problems. In my case 1.2 min download time. So I think the problem is somewhere inside sandstorm (different versions, or maybe something else). @davidjgraph I also don't have any proxy. And no I disagree 3.9 is large, but not a big deal, even if you'r download time >6 sec it sometimes fails.

[alderg]

@kentonv Can we add wire-compression in https://github.com/jgraph/draw.io/blob/master/etc/sandstorm/server.c%2B%2B somehow?

[kentonv]

Ah hah, indeed, it seems the real bug here is that no compression is being applied.

I think the best way to handle this would be to compress the Javascript at build time, and ship the file as .js.gz.

Here is an untested patch to server.c++ to make it recognize .gz:

kentonv/draw.io@eeb28b3

However, I wasn't able to figure out how to build the client files needed to actually test this out. Additional steps needed:

• gzip app.min.js during build to produce app.min.js.gz.
• Modify HTML to use this file instead of app.min.js.

[davidjgraph]

Thanks. I'll try and make some time to build this next week.

[timmc]

I encountered this today with draw.io and a sandstorm server on the same LAN as the client. Firefox downloads 2.9–3.2 MB in 5.4–5.6 seconds and then gives up. From curl I see a content-length of 4086277 and runtime of 5.4–6.1 seconds and varying quantities of bytes downloaded.

I don't think curl has a time limit for downloading the data. I'd say the lack of compression is a bug, but it seems there's also something in Sandstorm cutting off the download.

[davidjgraph]

I'm not going to get a chance to test this. If anyone wants to try I've improved the build instructions a little at https://github.com/jgraph/draw.io/tree/master/etc/sandstorm.

[kentonv]

@davidjgraph Thanks for the instructions! I now have a fully-working solution and have sent you a pull request: jgraph/drawio#33

[davidjgraph]

I've pulled it, but I'm getting an error creating a grain. I'll try to make some time to look into it further.

[kentonv]

@davidjgraph What kind of error? Is there an error message? Maybe you could post a screenshot?

[TechMD]

Hello, draw.io worked fine for me in sandstorm but now i can't open any diagrams and can't create any new one. I have not changed anything on my server (a VPS) ... always the same message. Do you have a step-by-step solution for a noob like me ? Thx

[davidjgraph]

We've a contractor starting next week who'll take over the Sandstorm work. Hopefully, she'll be able to put the build together and get Kenton's fix in.

[davidjgraph]

The fix is in release 6.5.4 of draw.io on Sandstorm.

[timmc]

I can confirm, thank you!

[JamborJan]

Awesome thanks, finally I can use all my sketches again.

[ocdtrekkie]

This one can be marked as closed.

[alderg]

Thanks!

[ocdtrekkie]

I suggested this could be closed in 2017. I am happy to now close it. :)