### Summary When I try to attach any image to any of my tickets I get an error: "Filenames contained invalid characters and could not be saved." The image filenames are valid, such as "Screenshot 2021-02-08 at 19.26.23.jpg" or "welcome remove exclamation mark.jpg". ### Steps to reproduce Ticket for instance: https://gitlab.com/ishayMuso/mm2000/-/issues/304 Try to attach an image. ### Example Project <!-- If possible, please create an example project here on GitLab.com that exhibits the problematic behavior, and link to it here in the bug report. If you are using an older version of GitLab, this will also determine whether the bug is fixed in a more recent version. --> ### What is the current *bug* behavior? When I try to attach any image to any of my tickets I get an error: "Filenames contained invalid characters and could not be saved." The image filenames are valid, such as "Screenshot 2021-02-08 at 19.26.23.jpg" or "welcome remove exclamation mark.jpg". ### What is the expected *correct* behavior? Images should be attached successfully. ### Relevant logs and/or screenshots See attached screenshot.  ### Output of checks This bug happens on GitLab.com #### Results of GitLab environment info