I have run into this issue a few times. When selecting to create an invoice the option to create from quote is not available and when I hover my mouse it states "there are no eligible quotes on this deal". However, we do have a signed quote attached to the deal. The quote expired, however, it has already been signed so I am unsure as to why I am not able to create an invoice from a signed quote. My expectation is that even if expired, as long as the quote has been finalized and signed, I should be able to create an invoice from that. Having to manually create the invoice defeats the entire purpose of having this process for me since I am having to recreate the same thing once again.