On OJS 126.96.36.199 we have the error message in the subject in step 3 of the submission process. In http://pkp.sfu.ca/support/forum/viewtopic.php?f=8&t=1223 you say:
Check your PHP configuration to ensure that file_uploads is enabled, upload_max_filesize and post_max_size are set to reasonable limits, and upload_tmp_dir is valid.
But I don't think it's this because when I skip step 3 I can upload a supplementary file.
Edit, adding this: I'm just trying to upload galleys which gives a similar problem: on the editing page of a submission I check "galley", choose my file, click "upload". The following page (where I have to save it) it doesn't show neither the original file name nor the file size Screenshot: http://i-jet.org/dl/screenshot.gif. When I preview the issue, I click the pdf-link, but the pdf doesn't open: blank screen.
Please help, this is urgent, thank you!