I used to be able to send my writings in office by email, not anymore?

I am writing a document on Libre Office Writer but I can`t send it to an email address. I get this message: I need to create an association with an email program. What does that mean, I have no problem sending email otherwise.
I need some help here please.

What is your OS and what do you normally use to send emails?

Have you defined which e-mail application to use? On my Linux-Mint version of LibO you choose the program by TOOLS>OPTIONS>INTERNET>E-mail and then select the E-mail application you use.

Chapter 10 of the Getting Started Guide > Printing, Exporting, E-mailing has useful information on this subject. You can download the manual or just the chapter from the Documentation web-site.

My OS is Microsoft Windows 10, 64 bit OS. When I click on tools ( and I assume you mean that little wheel that shows up when you click the windows icon ) there is no Options to be found. This may sound all pretty ignorant but I am not a Teckie.
When you talk about chapter 10 of the getting started guide you mean “Libre Office” guide, same with the documentation web-side?
Anyways my thanks for trying to help.

Click the Start button, click the cog wheel icon, type “default app” in the search box and Windows will get you to the default apps settings. Under Email you click on the icon of the currently default email app and select another one, that Libre recognizes. For instance, Thunderbird. LO doesn’t seem to recognize the Windows Mail app.

Does LO recognize Windows Mail app now? I recently ran into this same issue when I tried to send a document as a .doc file…