Requirements:
A) Any pom.xml file in droolsjbpm should not declare <version>, except for kie-dependency-with-dependencies. This way, all droolsjbpm modules work with the same version of a dependency and are certain to be compatible.
B) All dependencies that are also a dependency of EAP must use the same version EAP.

Designer, specifically the module jbpm-designer-backend, doesn't adhere to these requirements yet.

Recommended steps for jbpm-designer-backend:
1) Remove all dead dependencies first
2) Make a list of all dependencies that are not yet specified in kie-dependency-with-dependencies. Add them to kie-dependency-with-dependencies.
3) Compare that list with EAP's dependencies. If EAP uses a different version, specify the EAP version in kie-dependency-with-dependencies and temporarly overwrite it in the designer module with the designer's version.
4) The designer module will now only have <version> element that overwrite the version defined by kie-dependency-with-dependencies (which is in sync with EAP). Rmove all those <version> elements and fix any issues.

If 4) is not entirely possible, make a formal request to productization (dpalmer) for each dependency that is not in sync with EAP.