Apama Terracotta Integration

Hi everybody,
I need some help with Apama and Distribuited Memory Store Adapter.
I have created a Distributed Store called “apama_tc_store” that uses an ehcache.xml configuration file that I have properly references using a Custom property substitution variables (“ehcacheFilePath.apama_tc_store”).
Please find below the ehcache.xml file:

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:noNamespaceSchemaLocation="http://ehcache.org/ehcache.xsd" name="apama_tc_store">
	<cache name="alert_table" maxBytesLocalHeap="64M" eternal="true"
		memoryStoreEvictionPolicy="LRU" overflowToOffHeap="true"
		<terracotta consistency="strong" />
	<terracottaConfig url="localhost:9510" />

I have configured the monitor file to prepare/open the apama store (“apama_tc_store”) and to prepare/open the apama table (“alert_table”). See snippet below:

integer id := storage.prepareDistributed("apama_tc_store");		
		on Finished(id, *, *):f

action onStorePrepared(Finished f) {
		if not f.success then { log "Whoops1"; die; }
		store := storage.open("apama_tc_store");

		schema.fields := ["header", "item"];
		schema.types := ["string", "string"];
		integer id := store.prepare("alert_table", schema);		
		on Finished(id, *, *):f
	action onTablePrepared(Finished f) {
		if not f.success then { log "Whoops2"; die; }
		tbl := store.open("alert_table");		

However, when I run the correlator I get the following message:

2015-11-09 16:10:38.168 ERROR [12072] - Distributed MemoryStore store preparation error: java.lang.RuntimeException: Distributed MemoryStore 'apama_tc_store' could not be initialized (due to createTable error): java.lang.NullPointerException
	at com.apama.correlator.memstore.internal.DistMemStoreConfigManager.createStore(DistMemStoreConfigManager.java:332)
Caused by: java.lang.NullPointerException
	at com.apama.correlator.memstore.provider.bigmemory.Store.createTable(Store.java:139)
	at com.apama.correlator.memstore.internal.DistMemStoreConfigManager.createStore(DistMemStoreConfigManager.java:292)

2015-11-09 16:10:38.168 CRIT  [16872] - pippoMonitor [9] Whoops1

Can you please help me?
Thank you in advance