core data - addPersistentStoreWithType Returns Error 'attempt to insert nil key' for iCloud Storage -

i'm trying create core data storage in icloud, when try , add persistent store first time (expecting creation), error...

'-[__nscfdictionary setobject:forkey:]: attempt insert nil key'

i've seen couple of other similar posts, recommendations in code. here code snippet.

        // set options         nsurl *ubiquitouscontenturl = [ubiq urlbyappendingpathcomponent:@"transactionlogs"];         nsstring *storeubiquitouscontentname = @"progressdata";         nsdictionary *options = [nsdictionary dictionarywithobjectsandkeys:                                   ubiquitouscontenturl, nspersistentstoreubiquitouscontenturlkey,                                   storeubiquitouscontentname, nspersistentstoreubiquitouscontentnamekey, nil];          // url progress db         nsurl *progressurl = [ubiq urlbyappendingpathcomponent:@"documents/localdata.nosync/progressdata.sqlite"];          // create or open core data sql progress database         nserror *error = nil;         progressmodel = [[nsmanagedobjectmodel mergedmodelfrombundles:nil] retain];         progresscontext = [[nsmanagedobjectcontext alloc] init];         progresspsc = [[nspersistentstorecoordinator alloc] initwithmanagedobjectmodel:progressmodel];         [progresscontext setpersistentstorecoordinator:progresspsc];         [progresspsc lock];         [progresspsc addpersistentstorewithtype:nssqlitestoretype configuration:nil url:progressurl options:options error:&error];         [progresspsc unlock]; 

thanks ray

found issue. seems have create 'localdata.nosync' directory manually. doesn't created if doesn't exist.