Release 1.0.56.0b1 of TextMesh Pro has been submitted to the Asset Store and should be available within the next few days.
Please read the Release and Upgrade Notes before updating to this new release and always be sure to backup your projects first.
Here are direct links to download the latest releases for the indicated versions of Unity.
TextMesh Pro Release 1.0.56 - Unity 5.5
TextMesh Pro Release 1.0.56 - Unity 5.6
TextMesh Pro Release 1.0.56 - Unity 2017.1
TextMesh Pro Release 1.0.56 - Unity 2017.2
TextMesh Pro Release 1.0.56 - Unity 2017.3
*** Important Reminder ***
As per the Upgrade Note part of the Release Notes, before importing the new release of TMP, you have to first remove the previous version by deleting the “TextMesh Pro” folder.
Be sure to back up any files or assets you may have saved inside the TextMesh Pro folder hierarchy (you should not have but just in case) before deleting the folder. Be sure to review and note any changes you may have made to the TMP Settings file, Stylesheet and other assets.
Until TMP is part of the Unity installer, as you upgrade to new major releases of Unity (ie. 5.5, 5.6, 2017.1, 2017.2, etc.) you will also need to keep updating TMP to the matching release for that version of Unity.