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Community Member

Images sometimes appearing as broken, sometimes not

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Has anyone run into the situation where images in a page sometimes appear as broken (i.e.:257270_Screen Shot 2017-10-19 at 1.01.04 PM.png) and other times not?  Explanation?

The image was first uploaded to "Course Files" and embedded in a page using the image tool.

The HTML looks like this:

<p><img src="https://bostoncollege.instructure.com/courses/1578621/files/64634637/preview" alt="This is an Alt tag" width="500" height="375" data-api-endpoint="https://bostoncollege.instructure.com/api/v1/courses/1578621/files/64634637" data-api-returntype="File" />

While we're at it, if someone cares to explain some stuff in the code above,  it would satisfy a long standing curiosity.:

1) what is the function of <... data-api-endpoint="https://.../api/v1/courses/1578621/files/64634637" data-api-returntype="File"/>

2) In the first part of the image tag, if /preview is deleted, it gets replaced by /download.  The functionality doesn't seem to change.

Thanks.

1 Solution

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Community Team
Community Team

Hi Kimberly,
I checked with Support this AM and we are aware of this ongoing issue. Our technicians have been able to duplicate and document the cache issue. It has been escalated to the highest level in Support and our engineers are working on solving it now. The best thing you can do is update your tickets with any new information you uncover and if you believe you have a ticket that was marked resolved before we discovered that clearing cache did not permanently fix the issue, please update them to that effect.

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11 Replies
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Instructure
Instructure

Hello there, hesspe@bc.edu! In order to get some additional eyes on this, and because you have two different types of questions, I'm going to share this with two groups - the https://community.canvaslms.com/groups/admins?sr=search&searchId=4b09249d-4e3e-42cc-974d-c6e717796c9...‌ group and https://community.canvaslms.com/groups/canvas-developers?sr=search&searchId=f0a0e2e3-a6a1-4927-b6ee-...‌ group. Hopefully this helps you out!

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Community Member

Thanks for the curation!

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Adventurer III

Hi, Peter, 

Let me see if I can explain this right.

The endpoint is an attribute, its function is to provide a snippet reference for API users to know where a certain code is referenced.  so:

  • data-api-endpoint leads to a URL where the linked object can be accessed via the API
  • data-api-returntype refers to the type of data which is returned from the other side.

Well, if you are familiar with what API is,  you've already known what I am talking about now. If not, API (Application Program Interface) is a code that allows two software programs to communicate with each other. (In your case, it refers to your page getting an image saved in your file folder which hosted somewhere in Canvas' server). Sometimes when two programs talk, it is necessary to mark down the references of where the exchange of info took place, so that in case you want to trace back to the source, you know where it is located. More or less, it functions like a road sign, a snapped trim branch you used as a marker of a hiking route, I am bad at metaphor, but you get the meaning. 

For the disappearing graphics, there are too much unexpectable that can cause it. I would like to suggest use PNG format with reasonable file size.

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Community Coach
Community Coach

Hi hesspe@bc.edu

I can at least provide you with an answer to your second question.

Canvas is really a very large and complex relational data base and a collection of related applications. When you upload an image to course files (or your own files) it is being stored in a related application (or DB), then when that file is then added to a content area it is added via an API call to wherever it actually resides in Canvas (a link between the file space and the content area).

I know that for some this may seem like gobbledygook, and not really being a coder I have probably serious mangled the explanation, but I hope that helps.

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Community Coach
Community Coach

Hi hesspe@bc.edu,

I can jump in on the first one, we experienced something similar some months back, I undertook extensive testing to try to replicate, but could never reliably replicate it. 

Are you using Chrome per chance (as there is something that showed up in the developer console for us when that happened). When it happens again if you are in Chrome, could you please open up the developer console (without refreshing the page) and see if you have an error saying 'Failed to load resource: the server responded with a status of 401 (unauthorized)'. I am aware that Safari also contains a similar console, though is somewhat more involved to get access too.

Would be interested to see if you have that same 401 HTTP status on the image that does not load correctly. We have not seen it in a few months but were never able to narrow down the cause.

Cheers,
Stuart 

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Learner II

In case it helps...

Some may want to copy/paste the following information into their official Support Request (or reply to the response they received from Canvas Support)? Others have reported receiving generic type responses (clear cache, try a different computer...), which leads me to believe that Canvas may not yet be fully aware of the scope of this problem.

Here are some of the recent case numbers that others have posted to the Canvas Community about image related problems: #02672254, #02675969, #02687703. #02667582, #02676804, #02688690, #02690931. In case it helps the engineers, here are just some of the links to other conversations about this issue:

I will post this to some of these other conversations as well. 

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Community Team
Community Team

Hi Kimberly,
I checked with Support this AM and we are aware of this ongoing issue. Our technicians have been able to duplicate and document the cache issue. It has been escalated to the highest level in Support and our engineers are working on solving it now. The best thing you can do is update your tickets with any new information you uncover and if you believe you have a ticket that was marked resolved before we discovered that clearing cache did not permanently fix the issue, please update them to that effect.

View solution in original post

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Learner II

Hello Community...

I received the following update to my case #02672254... "engineers have deployed a temporary fix for this issue, which should allow images to show correctly for you in Canvas until a more permanent fix is in place." This issue did appear to be resolved when viewing my course as an instructor. 

However...

Joel Brown posted the following today at https://community.canvaslms.com/message/91785-re-images-embedded-in-pages-disappearreappear-at-rando... 

"I've had a few conversations with support regarding this issue. My most recent case: 02688342 was a little different to my previous ones. All images displayed correctly for me and when viewing the page as admin and also under 'student view' however when I log in as an enrolled student, the images did not display. I tested this on various computers in the office, chrome, FF, IE, clear cache etc without any resolution. It still only happened when logged in as an enrolled student."

So, I just wanted to pass along the 'heads-up'. Since I do not have 'admin' status (cannot 'masquerade' as a student  - only have the 'student view'), I will be calling call my institution's Canvas Help Desk first thing tomorrow when they open - to find out what they see when logged in as an enrolled student in my course. Other 'non-admins' may want to do the same?, and perhaps update their cases with Canvas engineers accordingly?

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Learner II

A quick update...

I inquired (via my ticket email) as to the embedded images for 'enrolled student' an received the following response:

Thank you for your reply to Canvas Support. I have checked on our tracker and our team is still working on this behavior and trying to correct it. At this time I don't have an ETA on when this will be resolved, but when our team does resolve this we will update you through your email and this ticket. If you would like us to check through your student's view in Canvas at some of the affected pages, could you share us links to those pages? If you have any further questions for Canvas Support, please let us know. We're happy to help where we can.

L1 Support
support@instructure.com

ref:_00DA0Ibsk._500A0ZCw5V:ref

So, I guess this issue is not fixed Smiley Sad. If anyone has better news, I would really love to hear from you. My students will be getting loaded into my courses in less than two days.

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