Resolution:
When attempting to use a GridServer 3 license file with a GridServer 4 system, an exception similar to the following will appear in the Manager log:

01/10/06 10:11:04.366 Severe: Could not read license: java.io.UTFDataFormatException: Invalid byte 1 of 1-byte UTF-8 sequence.

This happens because the license format between GridServer 3 and GridServer 4 has changed. The solution is to download and install a GridServer 4 version of your license.