xtext: java.lang.SecurityException: class "org.eclipse.core.runtime.OperationCanceledException"'s signer information does not match signer information of other classes in the same package

workaround

				<plugin>
					<groupId>org.eclipse.xtend</groupId>
					<artifactId>xtend-maven-plugin</artifactId>
					<version>${xtextVersion}</version>
					<dependencies>
						<dependency>
						    <groupId>org.eclipse.platform</groupId>
						    <artifactId>org.eclipse.equinox.common</artifactId>
						    <version>3.10.0</version>
						</dependency>
					</dependencies>

alternatively you can pin the jdt version of your xtext release e.g.

				<plugin>
					<groupId>org.eclipse.xtend</groupId>
					<artifactId>xtend-maven-plugin</artifactId>
					<version>${xtextVersion}</version>
				<dependencies>
					<dependency>
						<groupId>org.eclipse.jdt</groupId>
						<artifactId>org.eclipse.jdt.core</artifactId>
						<version>3.13.102</version>
					</dependency>
					
					<dependency>
						<groupId>org.eclipse.jdt</groupId>
						<artifactId>org.eclipse.jdt.compiler.apt</artifactId>
						<version>1.3.110</version>
					</dependency>
					<dependency>
						<groupId>org.eclipse.jdt</groupId>
						<artifactId>org.eclipse.jdt.compiler.tool</artifactId>
						<version>1.2.101</version>
					</dependency>
				</dependencies>

For those still using 2.10.0 and unable to move due to JDK dependency:

<dependency>
    <groupId>org.eclipse.jdt</groupId>
    <artifactId>org.eclipse.jdt.core</artifactId>
    <version>3.10.0</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jdt</groupId>
    <artifactId>org.eclipse.jdt.launching</artifactId>
    <version>3.10.0</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jdt</groupId>
    <artifactId>org.eclipse.jdt.debug</artifactId>
    <version>3.10.1</version>
</dependency>

The problem will be solved in Xtext 2.15 by having a fixed dependency to emf and jdt and platform

doing that it helps to create a new maven project and using the plugin as dependency (and not as plugin) then you can use the dependency hierarchy view in eclipse

Yup, that’s the trick I usually use when working on Maven plugins… (Shame there’s no plugin equivalent to dependency:tree since the results can still end up being different! Something else for the never-ending todo list.)

doing that it helps to create a new maven project and using the plugin as dependency (and not as plugin) then you can use the dependency hierarchy view in eclipse

@kittaakos did you try to specify the jdt core and equinox versions as they were with 2.11