If you are using RepreZen API Studio from within a standard Eclipse distribution, rather than using the standalone API Studio Desktop, you are likely to see that newly generated custom GenTemplate projects have red error markers. Error messages associated with these markers will be of the form:
<SomeClassName> cannot be resolved to a type.
We believe this is a problem with Eclipse build support for Xtend language processing. While it's not clear exactly what's going on, the workaround is very straightforward: Immediately close, and then re-open the editor that is left open following the project creation, for the project file MainGenerator.xtend. At that point, the project will rebuild automatically, and the error markers will clear.
Note that in releases prior to 1.6, the file left open after project creation is called MainTemplate.xtend. Closing and then reopening that file should clear project error markers.
We expect to fix this issue in a later release.