ERROR exception.ExceptionHandler - could not send email after exception Message: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead

[confile]

I use Grails 2.4.5 and the plugin 0.1.1.:

Here is my URL mapping:

      "403"(controller: "errors", action: "error403")
      "404"(controller: "errors", action: "error404")
      "500"(controller: "errors", action: "error500")
      "500"(controller: "errors", action: "error403",
            exception: AccessDeniedException)
      "500"(controller: "errors", action: "error403",
            exception: NotFoundException)

here is my Config.groovy

mailOnException.email.to = test@mydomain.com
mailOnException.email.from = other@mydomain.com

BuildConfig.groovy

        compile ":mail:1.0.7"
        compile ":asynchronous-mail:1.2"
        compile ":mail-on-exception:0.1.1"

When I create an Exception (500) I get the following error:

Message: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead
    Line | Method
->>   65 | doCall               in org.chai.exception.ExceptionHandler$_resolveException_closure2
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|     21 | sendAsynchronousMail in grails.plugin.asyncmail.AsynchronousMailService
|    128 | doCall . . . . . . . in AsynchronousMailGrailsPlugin$_configureSendMail_closure8
|     60 | resolveException     in org.chai.exception.ExceptionHandler
|    198 | doFilter . . . . . . in grails.plugin.cache.web.filter.PageFragmentCachingFilter
|     63 | doFilter             in grails.plugin.cache.web.filter.AbstractFilter
|     53 | doFilter . . . . . . in grails.plugin.springsecurity.web.filter.GrailsAnonymousAuthenticationFilter
|     62 | doFilter             in grails.plugin.springsecurity.web.authentication.logout.MutableLogoutFilter
|     46 | doFilterInternal . . in org.grails.jaxrs.web.JaxrsFilter
|   1145 | runWorker            in java.util.concurrent.ThreadPoolExecutor
|    615 | run . . . . . . . .  in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run                  in java.lang.Thread
Error |

[confile]

@fterrier Is there any workaround?