AE while saving cache

ERROR 16:07:05,499 Exception in thread Thread[OptionalTasks:1,5,main]
java.lang.AssertionError
        at org.apache.cassandra.config.CFMetaData.<init>(CFMetaData.java:314)
        at org.apache.cassandra.config.CFMetaData.<init>(CFMetaData.java:307)
        at org.apache.cassandra.cache.AutoSavingCache$Writer.<init>(AutoSavingCache.java:213)
        at org.apache.cassandra.cache.AutoSavingCache.getWriter(AutoSavingCache.java:74)
        at org.apache.cassandra.cache.AutoSavingCache.submitWrite(AutoSavingCache.java:176)
        at org.apache.cassandra.cache.AutoSavingCache$1.run(AutoSavingCache.java:90)
        at org.apache.cassandra.concurrent.DebuggableScheduledThreadPoolExecutor$UncomplainingRunnable.run(DebuggableScheduledThreadPoolExecutor.java:75)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:351)
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:178)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:722)