I'll give you some info this evening when I get home. What you will do is change the z-index of the chat bar to 100. The z-index on the message box is at 101.

1.Go to your arrowchat admin dashboard.
2.Go to appearance / templates
3. In the box with the css search for #arrowchat_base
4. I believe the z-index value for this element, before changing, is 1098. Change it to 100.
5. Click "Save Changes" at the bottom of the page.
What this will do is cause the chat bar to be behind the new message box allowing you to click the "send" button.
This works with the active arrowchat theme. If you change arrowchat themes, you will need to apply this to your other theme as well.

Note: Even on a no bar arrowchat theme; the bar is still there. It's just transparent.

:))) I told to the arrowchat your solution and they told me this:

" You wouldn't want to mess with the ArrowChat z-index as it'll mess other things up. Your best bet would be to change the z-index of that pop out window to something higher to appear above ArrowChat."

As usualy nobody told you nothing on the support page's :))) and they try to throw things in other's garden... :))

Edit later:

Another answer from arrowchat support:

" We can't tell you what z-index to change because that's not part of our product and we wouldn't know.

I can guarantee you that you don't want to change the z-index of ArrowChat. It will mess up our chat software. A much simpler solution is to change the z-index of that pop up window. "

So I'm back to the begining... :)

How can I see those button's ? :)

I have this setting on my site, and haven't seen any issues.If I do, it's just a simple change in the css.

OW Visuals The theme maker has provide the answer: 

Please save this code in to Admin>>Theme Edit>>CSS>>Edit CSS section:

.ow_chat_dialog_wrap {    position: fixed;    right: 265px;    bottom: -5px;    z-index: 1029 !important;}
It bring in front of the chat bar the pop up message window.

Okay. I was going to give you this to bring the message box to the front without moving it's position. Having it at the bottom can be important on smaller devices.

html .ow_chat_dialog_wrap {
    z-index: 1099;
}