Modifying existing FB in Simatic S7

I am doing modification of existing FB. After modification when i open the FB i got the message: 'The interface of the block was changed. After save/Load, this results in an interface conflict with the blocks that reference it. When this block is loaded, the CPU can go into STOP mode. Continue Save/Load ?'
So i saved the program and then do the File ---Check and update access. Then when i open the FB the message does not come. But still when i open the DB associate with this FB i am getting the message everytime :
'There are no parameter and local variable names available because there is a time stamp conflict between the interface of the block and the description of the parameter and local variable names'.

How can i get rid of this message. and when i download the FB in the PLC does it make any problem. Do i need to download first DB , then FB or first FB then DB.

Your reply will be appreciable.

the FB will be called - Probable in OB1
You need to Updated as well

The message you are getting is because you modified the data structure, i.e. added or taken away one or more of the IN, OUT, IN_OUT and STAT parameters.

The Instance DB is created when you first put a new FB call into your program, it contains the above parameters as they are seen in the FB parameter list.

Once its created it does not modify itself if you change the FB parameter structure. You have to do this manually.

To do this you have to go to each call point for that FB so that each IDB can be updated, right click the IDB and select update.

Once each DB has been updated the FB and DB's can be downloaded to the PLC. This can cause the PLC to stop if the DB is not big enough for the new FB during the download, or if the misaligned data causes an error.

The PLC can be inhibited from going into stop if you program OB121 and download it to the PLC first, it can be empty.

You need to be sure that this won't cause a safety problem during the download.

A safer method maybe to stop the process, disable any FB call by quoting out and then downloading both the FB and DB, then re-enabling the call.