@IsabellaRellis
Your image didn't come through, so I'll try an answer without the picture.
You didn't say how you are trying to open them and your description of the problem is consistent with how you're trying to open them rather than the files themselves.
Most software stores their files in a format that recognizable by the computer program that created the file, but not by a human. That is, you cannot open a JASP file with anything but JASP (or a program that specifically recognizes JASP) and have it make any kind of sense.
Excel files are the same way, although many programs will recognize the Excel .xlsx format (JASP is not one of those). Those Excel files are zipped, which means that if you were to open one with a text editor, you would see the letters PK at the start.
What you are describing makes it sound like you're trying to open one of those files with something other than the software that created it. This could happen is no file association for the type and it's opening with a text editor or other file viewer. In that case, what you're seeing is expected. The editor / viewer doesn't know how to interpret the file, so it gives you the content of the file. Those are binary files, not text files, and contain characters outside the normal range of usage.
You won't be able to view the files before submitting unless you open them with the software that recognizes those files. Try going into Excel or JASP and opening the file from there.
It can be confusing. JASP and Excel can read different file formats and the most common form for reading data into JASP is a CSV (comma-separated value) file. Those are plain-text files, so opening them with a text-editor should produce understandable results. You might be seeing those files, which look normal, and think you can open the output in the same way. The output files are different so you cannot open them in the same way and see anything that makes sense.
