Sometimes it is because of something wrong with your worksheet.  Sometimes it is because the website is overloaded.  I have one printable that I just can not uupload no matter what I do to change it.  When I have this problem in word - I cut and paste everything into a new document and save it as a new document.  Then it just uploads.  It maybe because you have pasted pictures into word straight frmo the internet - that use to cause problems...

 

I hope you are successful

Best wishes

Vicki