I thought I would flag this again, as it has happened several times now. If you allow Microsoft Word to name a file based on the content of the document there is a small risk that it may have an apostrophe in the file name.
For example if I created a document and the first piece of text in it said “Fred’s Success Story” and then saved it (without giving the file a name), Microsoft would save the file based on the first few words in the document. It might save it as fred’s success story.docx for example. Ordinarily there is nothing wrong with this until you try to add it to a WordPress website by uploading it as either a PDF or MS Word document. The presence of the ‘ in between the d and s will throw an HTML error on upload.
Look at the example I came across today below.
In the case above, I uploaded an auto-named file with the name: Burton on Trent Child Parents’ Information leaflet (1).pdf. While uploading to the uploads directory the file was rejected (HTML Error top left of the screen).
The fix is very simple, edit the file name to remove any punctuation marks or symbols in the file name. This will resolve the problem.
Why does it do this?
It is detected and blocked probably because there is a way of attacking the website or asserting control over the website by injecting special characters. I don’t know the precise reason, but it is probably something to do with this.
Still stuck? Contact me for help.