PropertyValidator.cs wixVariablesValidationRegex
This regex is disallowing variables such as:
WixUILicenseRtf=LICENSE.rtf
(doesn't like the period)
Placing this variable in the project file works fine in builds. However, if you go to the project settings in Votive, it will remove the variable (and clear your build type, as in forgets that you are building an MSI).
Logged In: YES
user_id=991639
Originator: NO
Validation code was too strict and was removed.