Test execution failures since upgrade to 2017.3.2 build IC-173.4127.27

Since upgrading to the latest version of 2017.3.2 I've started running into all sorts of issues when running JUnit tests.

Test resources no longer seem to get automatically copied during a build, and it's even not compiling test classes.

Have any setting changed in the last update?

IntelliJ IDEA 2017.3.2 (Community Edition)
Build #IntelliJ IDEA 2017.3.2 (Community Edition)
Build #IC-173.4127.27, built on December 25, 2017
JRE: 1.8.0_152-b16 amd64
JVM: Java HotSpot(TM) 64-Bit Server VM by Oracle Corporation
Windows 7 6.1, built on December 25, 2017
JRE: 1.8.0_152-b16 amd64
JVM: Java HotSpot(TM) 64-Bit Server VM by Oracle Corporation
Windows 7 6.1