Hi @jai1 and welcome to the Canvas Community. I'm guessing that you're the teacher on the course where the students are trying to access the presentations. There are a few reasons that students might get the "Access denied" message when trying to access a piece of Canvas content and it's often down to publishing. You need to check that the content item itself is published and if the item is part of a module, check that the module is also published. Also check that the course is published - if it isn't then students won't be able to view any content within it. You haven't said what type of content it is - a page, file, assignment etc. If it's a file then go into the course files area and check that as well as being published, the file doesn't have any other restrictions such as availability dates.
If the content is part of a module then check if the module has any restrictions - for example is it locked until a specified date or do students have to complete a previous module before viewing this one.
As community members don't have access to Canvas courses for individual schools/colleges, we can't check your course directly to see what's causing the problem so you might need to speak to the local technical support team at your college, or log a ticket with Canvas support via the help menu.
