Quote Originally Posted by bsacheri View Post
I just had to troubleshoot this issue and found a solution that may work for you.

If sheet you are experiencing the issue on currently has a filter applied, you won't be able to use the Fill Series feature. It will only copy the top value down.

I don't have enough reputation on this site to post a link to the site I credit for the answer, but you can Google: repairmsexcel resolve-excel-fill-handle-not-working-issue
THANK YOU! This is what caused the numbers not to auto fill series, its the bloody FILTER.

So in order to enable or re-enable autofill series or numbers by clicking on the bottom corner right of the cell and dragging it down/across, remove whatever filter there is at the top of its table.

Otherwise you might keep getting stuck with a Quick Analysis pop up option which wont help the autofill even if you remove it from options.

Once again, thank you bsacheri!