Could not modify sqlite file after copying it to new path in ios

In my app I have sqlite file & I want to copy that file to another path. I have the following code. but when I copy it I found that all data is not copied to the new file. If I have new File then next time before copying I have to delete file(Replacement of file with new data) & copy the new file at same path. If again I copied the data to new path & if all data is copied to new path that time I can not modify the old sqlite file. I don't understand why I can't modify database after all data is copied. & how do I come to that all data is successfully copied? what are the ways to achieve this. If anyone want any extra information I will provide you.

NSArray *paths =
NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory,
                                    NSUserDomainMask, YES);
NSString *applicationSupportDirectory = [paths firstObject];
NSString *str=[NSString stringWithFormat:@"%@/XMPPMessageArchiving.sqlite",applicationSupportDirectory];//copy this file

NSString *fileName = [NSString stringWithFormat:@"XMPPMessageArchiving.sqlite"];
NSURL *ubiq = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil];


NSFileCoordinator *coordinator = [[NSFileCoordinator alloc] initWithFilePresenter:nil];

NSURL *fromURL = [NSURL fileURLWithPath:str];
NSURL *toURL = [[ubiq URLByAppendingPathComponent:@"Documents"]
                URLByAppendingPathComponent:fileName]; 

[coordinator coordinateReadingItemAtURL:fromURL options:NSFileCoordinatorReadingForUploading writingItemAtURL:toURL options:0 error:nil byAccessor:^(NSURL *newReadingURL, NSURL *newWritingURL)
 {

     NSFileManager* fileManager = [[NSFileManager alloc] init];
     BOOL fileExists = [fileManager fileExistsAtPath:newWritingURL.path];
     if (fileExists)
     {
         [fileManager removeItemAtURL:toURL error:nil];
     }

     NSError *error=nil;
     [fileManager copyItemAtURL:newReadingURL toURL:newWritingURL error:&error];

 }];