If students are receiving the following error message, it is because the Submission folder has Originality Checking (TurnItIn) enabled, and their file cannot be evaluated by Turnitin:
Your submitted files do not meet the file restrictions for this assignment. Please make sure your file is less than 40 MB and is one of the following file types: html, doc, docx, hwp, odt, rtf, wpd, txt, ps, pdf, pptx, ppt, ppsx, pps, xls, xlsx, gdoc.
D2L submission folders with Originality Checking enabled are restricted to only file types that TurnItIn can evaluate, and those include html, doc, docx, hwp, odt, rtf, wpd, txt, ps, pdf, pptx, ppt, ppsx, pps, xls, xlsx, gdoc files. The files must also be less than 40 MB. Turnitin offers a detailed explanation of the accepted text-based file types here.
If students need to submit files that TurnItIn cannot evaluate, such as data files, movies, images, etc., then you have two options for remedying the issue. If you are asking students to submit a set of documents that includes text files you want evaluated by TurnItIn, as well as media files, option 2 is the best solution.
Option 1: Remove Originality Checking from the Submission folder. Students will be able to submit a wider range of file types, as detailed here.
Option 2: Create a second Submission folder for students to submit their media or data files, and do not enable Originality Checking. Students will submit their text-based files to the original Submission folder that has Originality Checking enabled, and their media or data files to the second Submission folder that does not have Originality Checking enabled.
You can read more about using Submission folders and Originality Checking in our D2L Submissions guide. For an explanation of another common Submission folder error, please see this post.