How to reproduce:
1. Open the attached Project
2. In the Hierarchy menu click on the Cube object
3. In the Inspector click on the Tag -> "Add Tag", click on the "+" sign and type in any name for the tag
4. Remove the tag by clicking the "-" sign and create another one right after with any name
5. Attach the newly created tag to the Cube object and Build the Project

Expected result: The Text Shows the tag's name
Actual result: The Text fails to show the tag's name in the Build

Reproduced in: 2018.3.0a3, 2018.2.0b9, 2018.1.7f1, 2017.4.6f1, 2017.2.3p2, 2017.1.4p2