Creating a Project or Repository Fails With HV000041: Call to TraversableResolver.isReachable() threw an exception

javax.validation.ValidationException: HV000041: Call to TraversableResolver.isReachable() threw an exception.
        at org.hibernate.validator.internal.engine.ValidatorImpl.isValidationRequired(ValidatorImpl.java:1230) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraint(ValidatorImpl.java:438) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:387) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:351) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:303) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validate(ValidatorImpl.java:133) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.springframework.validation.beanvalidation.SpringValidatorAdapter.validate(SpringValidatorAdapter.java:109) ~[spring-context-4.0.2.RELEASE.jar:4.0.2.RELEASE]
        at org.springframework.validation.DataBinder.validate(DataBinder.java:760) ~[spring-context-4.0.2.RELEASE.jar:4.0.2.RELEASE]
        at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.validateIfApplicable(ModelAttributeMethodProcessor.java:161) ~[spring-web-4.0.2.RELEASE.jar:4.0.2.RELEASE]
        at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:109) ~[spring-web-4.0.2.RELEASE.jar:4.0.2.RELEASE]
        at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:79) ~[spring-web-4.0.2.RELEASE.jar:4.0.2.RELEASE]
        at com.atlassian.applinks.core.rest.context.ContextFilter.doFilter(ContextFilter.java:25) [applinks-plugin-4.1.1_1389362838000.jar:na]
        at com.atlassian.stash.internal.spring.security.StashAuthenticationFilter.doFilter(StashAuthenticationFilter.java:92) [StashAuthenticationFilter.class:na]
        at com.atlassian.stash.internal.web.auth.BeforeLoginPluginAuthenticationFilter.doInsideSpringSecurityChain(BeforeLoginPluginAuthenticationFilter.java:111) [BeforeLoginPluginAuthenticationFilter.class:na]
        at com.atlassian.stash.internal.web.auth.BeforeLoginPluginAuthenticationFilter.doFilter(BeforeLoginPluginAuthenticationFilter.java:77) [BeforeLoginPluginAuthenticationFilter.class:na]
        at com.atlassian.security.auth.trustedapps.filter.TrustedApplicationsFilter.doFilter(TrustedApplicationsFilter.java:100) [atlassian-trusted-apps-core-3.0.3.jar:na]
        at com.atlassian.oauth.serviceprovider.internal.servlet.OAuthFilter.doFilter(OAuthFilter.java:61) [atlassian-oauth-service-provider-plugin-1.9.1_1388446698000.jar:na]
        at net.bull.javamelody.JspWrapper.invoke(JspWrapper.java:150) [javamelody-1.50.0.jar:na]
        at net.bull.javamelody.JdbcWrapper$DelegatingInvocationHandler.invoke(JdbcWrapper.java:281) [javamelody-1.50.0.jar:na]
        at com.sun.proxy.$Proxy1571.forward(Unknown Source) [na:na]
        at com.atlassian.security.auth.trustedapps.filter.TrustedApplicationsFilter.doFilter(TrustedApplicationsFilter.java:100) [atlassian-trusted-apps-core-3.0.3.jar:na]
        at com.atlassian.oauth.serviceprovider.internal.servlet.OAuthFilter.doFilter(OAuthFilter.java:61) [atlassian-oauth-service-provider-plugin-1.9.1_1388446698000.jar:na]
        at com.atlassian.stash.internal.web.auth.BeforeLoginPluginAuthenticationFilter.doBeforeBeforeLoginFilters(BeforeLoginPluginAuthenticationFilter.java:89) [BeforeLoginPluginAuthenticationFilter.class:na]
        at com.atlassian.stash.internal.web.auth.BeforeLoginPluginAuthenticationFilter.doFilter(BeforeLoginPluginAuthenticationFilter.java:75) [BeforeLoginPluginAuthenticationFilter.class:na]
        at com.atlassian.stash.internal.request.DefaultRequestManager.doAsRequest(DefaultRequestManager.java:73) [stash-service-impl-2.12.0.jar:na]
        at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:202) [javamelody-1.50.0.jar:na]
        at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:180) [javamelody-1.50.0.jar:na]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.7.0_51]
        at java.lang.Thread.run(Unknown Source) [na:1.7.0_51]
        ... 203 frames trimmed
Caused by: java.lang.IllegalStateException: java.lang.ClassNotFoundException: Can't find a delegate
        at net.bull.javamelody.JpaPersistence.guessDelegate(JpaPersistence.java:176) ~[javamelody-1.50.0.jar:na]
        at net.bull.javamelody.JpaPersistence.loadOrGuessDelegate(JpaPersistence.java:144) ~[javamelody-1.50.0.jar:na]
        at net.bull.javamelody.JpaPersistence.getProviderUtil(JpaPersistence.java:129) ~[javamelody-1.50.0.jar:na]
        at javax.persistence.Persistence$1.isLoaded(Persistence.java:111) ~[hibernate-jpa-2.1-api-1.0.0.Final.jar:1.0.0.Final]
        at org.hibernate.validator.internal.engine.resolver.JPATraversableResolver.isReachable(JPATraversableResolver.java:57) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.resolver.DefaultTraversableResolver.isReachable(DefaultTraversableResolver.java:130) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.resolver.SingleThreadCachedTraversableResolver.isReachable(SingleThreadCachedTraversableResolver.java:46) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.isValidationRequired(ValidatorImpl.java:1221) ~[hibernate-validator-4.3.1.Final.jar:4.3.1.Final]
        ... 29 common frames omitted
Caused by: java.lang.ClassNotFoundException: Can't find a delegate
        ... 37 common frames omitted