我是第一次尝试将Grails应用程序部署到Heroku，并且按照日志成功部署了它：
|Done creating WAR target/PatientBoards-0.1.war
-----> No server directory found. Adding webapp-runner 7.0.57.2 automatically.
-----> Discovering process types
Procfile declares types -> (none)
Default types for buildpack -> web
-----> Compressing... done, 132.4MB
-----> Launching... done, v5
https://patientboards.herokuapp.com/ deployed to Heroku
但是当我转到https://patientboards.herokuapp.com时，页面是空白的！虽然我在本地尝试过，但应用程序运行正常。
我在日志中找到了这个：
2015-11-24T23:22:38.752616+00:00 app[web.1]: INFO: Illegal access: this web application instance has been stopped already. Could not load net.sf.ehcache.store.disk.DiskStore$KeySet. The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
2015-11-24T23:22:38.752617+00:00 app[web.1]: java.lang.IllegalStateException
2015-11-24T23:22:38.752618+00:00 app[web.1]: at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1612)
2015-11-24T23:22:38.752618+00:00 app[web.1]: at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
2015-11-24T23:22:38.752619+00:00 app[web.1]: at net.sf.ehcache.store.disk.DiskStore.keySet(DiskStore.java:610)
2015-11-24T23:22:38.752624+00:00 app[web.1]: at net.sf.ehcache.store.disk.DiskStorageFactory$DiskExpiryTask.run(DiskStorageFactory.java:817)
2015-11-24T23:22:38.752625+00:00 app[web.1]: at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
2015-11-24T23:22:38.752647+00:00 app[web.1]: at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
2015-11-24T23:22:38.752648+00:00 app[web.1]: at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
2015-11-24T23:22:38.752648+00:00 app[web.1]: at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
2015-11-24T23:22:38.752649+00:00 app[web.1]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
2015-11-24T23:22:38.752649+00:00 app[web.1]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
2015-11-24T23:22:38.752650+00:00 app[web.1]: at java.lang.Thread.run(Thread.java:745)
2015-11-24T23:22:38.752651+00:00 app[web.1]:
2015-11-24T23:25:38.811300+00:00 app[web.1]: Nov 24, 2015 11:25:38 PM org.apache.catalina.loader.WebappClassLoader loadClass
2015-11-24T23:25:38.811307+00:00 app[web.1]: INFO: Illegal access: this web application instance has been stopped already. Could not load net.sf.ehcache.util.concurrent.ConcurrentHashMap$ValueIterator. The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
2015-11-24T23:25:38.811309+00:00 app[web.1]: java.lang.IllegalStateException
2015-11-24T23:25:38.811310+00:00 app[web.1]: at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1612)
2015-11-24T23:25:38.811311+00:00 app[web.1]: at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
2015-11-24T23:25:38.811312+00:00 app[web.1]: at net.sf.ehcache.util.concurrent.ConcurrentHashMap$ValuesView.iterator(ConcurrentHashMap.java:3252)
2015-11-24T23:25:38.811312+00:00 app[web.1]: at net.sf.ehcache.statistics.extended.ExtendedStatisticsImpl$1.run(ExtendedStatisticsImpl.java:104)
2015-11-24T23:25:38.811313+00:00 app[web.1]: at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
2015-11-24T23:25:38.811314+00:00 app[web.1]: at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
2015-11-24T23:25:38.811315+00:00 app[web.1]: at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
2015-11-24T23:25:38.811315+00:00 app[web.1]: at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
2015-11-24T23:25:38.811316+00:00 app[web.1]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
2015-11-24T23:25:38.811317+00:00 app[web.1]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
2015-11-24T23:25:38.811318+00:00 app[web.1]: at java.lang.Thread.run(Thread.java:745)
2015-11-24T23:25:38.811319+00:00 app[web.1]:
2015-11-24T23:27:24.541959+00:00 heroku[router]: at=info method=GET path="/" host=patientboards.herokuapp.com request_id=264982a9-7c89-492d-bf01-0aa72639cd75 fwd="176.61.71.119" dyno=web.1 connect=0ms service=28ms status=404 bytes=128
我错过了什么吗？
由于