MathType requires a newer version of MT Extra warning message
TechNote 84
Applicability
The information on this page applies to: | |
---|---|
MathType 6 and later | Windows and Mac |
Issue
When launching MathType 7 either by itself or within another application, users sometimes receive the following error message…

…despite having successfully installed MathType 7 and even used it previously without receiving an error. Pressing the OK button will allow MathType 7 to run, but empty boxes will replace several essential characters in equations.
Reason
The original version of MT Extra, which is still distributed with many word processing, publishing, and test generation programs, contains only 43 characters:

The enhanced version of the MT Extra font included with MathType contains 145 characters:

When MathType 7 is launched, it checks the version of the installed copy of MT Extra extra. If an older version is installed, the expected characters will be replaced by empty boxes.
It is essential to understand how Windows and macOS handle fonts in their Fonts folders to understand this problem. In Windows, if multiple files exist for the same font, only one will be displayed in the Fonts Control Panel. Windows may be using an older version of MT Extra, even though the newer version has been properly installed. On the Mac, if Word happens to install all of its fonts into the per-user fonts folder for some reason (maybe an Office reinstallation, etc.), MathType 7 may not find the newer/correct version of MT Extra, and the above warning will appear. MathType 7 for Mac lists the path to the older MT Extra file, which is helpful as it could be in several places.
If you reinstall or upgrade your word processor, manually install the equation editor that comes with your word processor, install a new program that contains an equation editor, apply a service release or patch or update to your word processor, or use the "Detect and Repair" feature that comes with Microsoft Office, very often these installers will overwrite the version of MT Extra that comes with MathType 7 resulting in an error message when launching MathType 7 because the newer, enhanced version of MT Extra has been replaced with an older version.WS
Solution
The simplest way to address this problem is to reinstall MathType 7 If you downloaded MathType 7 and no longer have the installer, you can download another copy from our Downloads page, but please make sure to download the version you are licensed for. If you are licensed for MathType 6.9 and download MathType 7.4, your product key will not work.
Suppose you are familiar with the Fonts Control Panel and Windows Explorer or the various font locations in macOS. In that case, you could manually install the MathType 7 version of MT Extra after removing extra copies of MT Extra from your system per the instructions below.
Manually installing the MathType version of MT Extra
You can manually install MT Extra, but you should first remove all the copies already installed on your computer.
Windows 8 and later
It's best to have only one copy of a font on your system. In the latest versions of Windows, deleting a font isn't impossible, but doing so is more trouble than necessary. Simply open a File Explorer window, navigate to C:\Program Files\MathType\Fonts\TrueType [for 64-bit Windows it will be C:\Program Files (x86)\MathType\Fonts\TrueType], and double-click mtextra.ttf. In the font preview window, click and answer Yes if it asks you whether you want to replace it.
Windows versions up to Windows 7, 32-bit
Note
Because only one copy of MT Extra will be shown in the Fonts Control Panel at a time, you must refresh your fonts list after deleting each copy of it so that if another copy of MT Extra is in your fonts folder, it will appear. It may be necessary to delete and refresh your list several times to delete all copies of MT Extra. If another copy of MT Extra appears in your fonts list, the actual file name for the font will be different.
Choose Control Panel from the Start menu.
Open Fonts.
Look for the MT Extra font and delete it.
Close the window and repeat the first three steps. (It's not sufficient to press F5 to refresh your list of fonts. Doing so won't reveal any additional copies of MT Extra that are present.)
Look for the MT Extra font again. If it appears, delete it and close the window again.
Continue steps 1-5 until MT Extra no longer appears in your list of fonts.
From the File menu of the Fonts Control Panel, choose "Install new font". There is a copy of the enhanced version of MT Extra in
\MathType\Fonts\TrueType
.Note
The file you want is mtextra.ttf (the "ttf" may not be showing on your computer, but the "mtextra" will be). Do not be misled by the similarly-named font "Mt Extra Tiger.ttf". Reinstalling that one won't help.
Click MT Extra, and click OK.
MT Extra should be installed into your Fonts folder, and you should no longer receive an error message when launching MathType 7
Windows 7 64-bit
Navigate to C:\Program Files (x86)\MathType\Fonts\TrueType
Locate the font MT Extra.
Note
The file you want is mtextra.ttf (the "ttf" may not be showing on your computer, but the "mtextra" will be). Do not be misled by the similarly-named font "Mt Extra Tiger.ttf". Reinstalling that one won't help.
Right-click it and from the contextual menu, choose Install New Font.
MT Extra should be installed into your Fonts folder, and you should no longer receive an error message when launching MathType 7
Mac
From the Applications folder, open Font Book.
Look through the list of fonts for MT Extra. If it exists, remove or disable it.
From the File menu, choose Add Fonts.
In a Finder window, navigate to Applications\MathType 6\Fonts\TrueType and double click MT Extra.
Note
The file you want is mtextra.ttf (the "ttf" may not be showing on your computer, but the "mtextra" will be). Do not be misled by the similarly-named font "Mt Extra Tiger.ttf". Reinstalling that one won't help.
Since the enhanced MT Extra is now in your macOS Fonts folder, you should no longer receive an error message when launching MathType 7

We hope this has been helpful. As always, please let us know if you have questions about this or if you have additional techniques that work. We'd love to hear from you.