Getting two errors when opening attachments after updating to latest version of Thunderbird. First one is exception "cannot call openModalWindw on a hidden win

Question

After the last Thunderbird update 24.4.0, attachments no longer open. Attempt to open attachment flashes a message quickly but not long enough to read. I get the following errors in the error log with every attempt to open a document like word.
[Exception... "Cannot call openModalWindow on a hidden window" nresult: ox80040111 (NS_ERROR_NOT_AVAILABLE)" location: "JS frame :: resource://gre/components/nsPrompter.js::openModalWindow::line 382" data: no]
resource://gre/components/nsPrompter.js
The second error is
TypeError: this._taskbar is null
resource://gre/modules/DownloadTaskbarProgress.jsm
Under tools I have Word docs set to open with Microsoft Word. What are these errors and why can't I no longer open Word documents?
In addition I also receive multiple warnings at the same time such as Unknown property 'mso-style-type'. Declaration dropped.
{mso-style-type:export-only;
Expected '{' to begin declaration block but found 'WordSection1'.
@page WordSection1
DCar

Answer 1

What happens when you save the attachment to disk and open it with Word?