Showing results for 
Search instead for 
Did you mean: 
Community Member

LTI assignments still turned in after being locked

Can anyone explain why students are able to submit their Google LTI external tool assignments after the Canvas assignment has been locked? I wanted them to be able to submit their final in a Google Doc so I could use the plagiarism check feature.  I locked my final exam for 3pm, but I still had a student able to submit her work at 3:38pm. I double checked dates and times and everything and nothing is amiss.

Any guesses why an assignment has the feature to be locked if it's not really?? 

0 Kudos
8 Replies
Community Champion

@JenniferLeonard Did you set an "Until Date" in the Canvas assignment?  With just a due date, Canvas lets students submit after and then it should get marked late in the gradebook.   If you want to prevent them from being able to submit or access the assignment, regardless of it being the external tool (Google LTI) you need to put an until date in.

-Hope this helps!


Yes, the until date was set for June 2nd at 3pm and a student was still able to submit her LTI doc at 3:38 pm. 

Community Champion

I am wondering (especially with the time being that close to the cut off) if since the Google LTI is opening up a new screen, if as long as they open it by the "until" time, Canvas does not block the submission.  Normally if you try and access something after the until time, it tells you it is locked but if they already had the Google doc open, prior to the time locking it, if maybe they are able to still submit it.  Basically, the until time blocks access to the assignment but if you already have the access, does it block the submission???

I don't have access to a real student right now to test my theory but I could see that working.


Community Champion


I am just thinking out loud here.

I wonder if it's because it's an LTI (external tool) submission. External tools are not generally aware of the assignment settings in Canvas, so it wouldn't know that the availability date had passed.

You might think that Canvas shouldn't accept any submissions after the lock date, but tools are not required to immediately submit information back (I'm thinking about grade passback here, but it might apply to any type of submission) to Canvas. Some tools need the instructor to do processing before the submission is returned to Canvas. If there was a network error when the student made the submission in the tool and the tool didn't retry until it was successful, then Canvas would not know that the student had turned in something -- thus, the ability to submit after the lock date is kind of important.

I did a bunch of searching for other cases where submissions from external tools had been turned in after the lock date and couldn't find anything. That suggests that few people are using the lock dates, no one has noticed this before, or that something isn't acting right. It might be stretching to think that Google is aware of the lock date and determined that the document hadn't changed since before then so it allowed the submission. More likely is that the student tried to submit before 3 pm inside Google, but that it didn't get transferred to Canvas until 3:38 pm. The question is whether Google is sending the submission time or Canvas is using its own timestamp.

Testing would be needed to determine more, but I can think of reasons why it would accept something after the lock date. In my external tools, I set the date and time there rather than relying on Canvas to pass that information along (because it doesn't for my tool).

@James I think you're right about LTI not conforming to Canvas's assignment structures. So I have a few students in class with me now and I've just asked them about how the LTI external tool and the Google Cloud external tool have them submit their work. The Google Cloud external tool has students use the submit button in Canvas, but the Google LTI external tool (which is the only one I can use since the Google Cloud external tool glitches have caused me MAJOR issues since about October), my students say the submit button is through Google, not Canvas. And as far as I know in my use of Google Classroom, Google will only time stamp and identify that it's "done late", but it still allows for submissions. 

I don't usually lock assignments so I haven't noticed this issue before now, but I've had to use the LTI external tool exclusively since October/November of last fall. Based on our district tech's research into my glitch issues, the Google Cloud external tool was Canvas's product in order to integrate Google into it's platform, but now that Google has created their LTI external tool we suspect Canvas isn't going to try to improve on their Cloud option since Google has created its own (hence why the bugs that are causing me issues with using the Google Cloud external tool are not being addressed). 

So knowing that Google Cloud external tools was a Canvas solution, it makes sense why students who are doing assignments that way submit via Canvas and hence could be locked out of submission. And everything I know about Google Classroom is that they don't have a feature where we can lock assignments, so if students are submitting their Google LTI assignments via Google's button and not Canvas's button, it makes sense why even after I've locked the assignment in Canvas, they can still submit. I'm not 100% sure, but I suspect because she had opened it earlier she could still submit it. (I've got another student who I can do some more investigating with, but from what she reported about another assignment in a different class, she wasn't able to open the document or submit in Canvas after the assignment had closed).

Since the LTI feature is here to stay, I think that there's going to be a lot of instructors who are currently using the Google Cloud external tool and are going to be surprised to find that the LTI external tool won't really allow for a teacher to truly lock that assignment. I'm thinking either not enough people are using the LTI option for it to be an issue yet, or most LTI users aren't assignment lockers. But it's ultimately a Google/ Google Classroom design flaw, from my perspective, that doesn't mesh with the Canvas platform as much as users would like. I can see Canvas just punting the issue back to Google. 

Or then again, it could just be me. Am I looking at the issue incorrectly? Do you think it could be something Canvas could address? 


I was just looking at the Assignment Selection Placement standard while researching for another post here in the Community. It allows for the LTI to either specify the date/time when it was submitted or let Canvas decide. That means that the 3:38 might be when it was submitted to Google or when Google submitted it to Canvas. I don't know which the Google LTI is using. The 3:38 pm might be when they submitted it inside Google or when they Google submitted it to Canvas.

I'm a big fan of education. That is, clearly communicate to the students "Google may allow you to submit this after the lock date, but I will not accept or grade any items after that date." Then stick to it. Students can choose to ignore you, but if you have it documented, then they can't come back and argue the point (as in a grade appeal). Possibly related, my wife says that my instructions are too long and students don't read them -- maybe it's because I'm always communicating the quirks of Canvas to the students.

The one time I tried to use it, it didn't work for a bunch of the students, so I stopped using it. I'm off for the summer, so I don't have a class I can test it out on or get feedback from.

Is the Google Cloud external tools a Canvas solution? I tried to find that out when replying last night, but I have read recently that the Microsoft 365 cloud solution is provided by Microsoft and issues should be directed to them.

Community Champion

@James Google Cloud Assignments (the original connection) was developed by Canvas and is going away sometime this fall.  The date changed and I lost track, it was September.  The Google LTI 1.3 was developed by Google and they are handling development of it moving forward.  There is LOTS of comments about it on the Google support boards and they have developed a way for the Google Domain Administrator for the school to deem who the Canvas Administrator is so they can get direct support for the LTI. 

@James I will say that when I looked at that individual student's edit history for the assignment, it showed her first "edit" was at 11:45 am (nothing was written, that first one is usually the time stamp for when they open the assignment--also a nice LTI feature since I can see if they even actually opened it up), then again at 3:12pm was her first line written, then periodic time stamps from 3:12pm until her last one at 3:38pm. So I'm guessing it's the submission inside of Google instead of when Google sends it to Canvas.