I am having this same problem. Upon first creating a new Knowledgebase FAQ, whatever I type is
saved. If I have added an attachment as part of creating the new article
however, the attachment is not saved to the newly created KB article. I
can then open my just-created article, add my attachment, and the
attachment will still be there after I save the article a second time.
This issue is not browser specific, as it manifests in Firefox 42, Chrome 46, and IE 11.
It also happens for any size attachment, and with multiple document types (pdf, doc, txt, zip)
osTicket v1.9.12 (although I think it has been happening since 1.9.7), Apache 2.2.22, MySQL v5.5.46, PHP v5.3.10-1ubuntu3.21