The good old forum bug with the empty answer field when you click on post is back, so either copy the text inside to your clipboard
before posting, use a browser extension or the Preview function of SMF 
What do you mean back! it never left, happens every couple of days for me.
Another issue is smilies still don’t function on the Avast forum when using Edge browser, the other forums I use have all modified their settings for Edge to work correctly now but it hasn’t happened here yet.
Yep, it never left.
Using the Preview function first is no guarantee that it won’t get eaten by the forum bug. I frequently preview my post for layout and typo checks and still get bitten by the bug.
For me the only solution I can offer is the firefox add-on, Form History.
Apparently not enough posts for those that maintain this forum have been eaten or,
this would already have been fixed.
It’s a genuine pain when it happens on a fairly large post.
I copy the contents, then preview the post, then actually hit the post button.
Then I prey.
I just hit the back button and my text is there again.
If I hit post again, the message is posted fine.
Doesn’t work in firefox as it refreshes the page (so no text in the Reply window) when using the back button.
Same thing for me with Chrome.