Groovyc: unable to resolve class ...

When I try to compile my Grails 2.2.4 project on IntelliJ 14.1.1 running on Oracle JDK 8u40 on OS X 10.10.2, I get the attached compilation errors.

Many are of the form:

Error:Error:line (<#>)Groovyc: unable to resolve class <className>

where <#> is the line number, and <className> is a fully qualified class name.

Some of the unresolvable classes are our own, some are from Grails plugins, etc.

I can debug & run my Grails project just fine, but I can't get IntelliJ to compile it without running or debugging the project.

Attached are the pertinent .iml files.

Can anyone help?

If you need more info, please let me know and I'll supply it.

Thanks.