Hard to say what the issue is without seeing the error codes from  the blocks.

Would need to see ERROR, DONE, BUSY and STATUS.

Be aware, you will have to store these as they are only valid for 1 PLC cycle.

Along the lines of:

IF STATUS <> SAVED_STATUS THEN
    SAVED_STATUS := STATUS;
END_IF;

The Modbus blocks MUST be producing some values on the block status outputs.

Without this information it is not possible to say what the issue is.

The error code decodes as:

What type and structure is data block DB3?

What are the settings for the other parameters to the block (e.g. MODE, DATA_ADDR)? 

There still seems to be something wrong with your DATA_PTR:

This post might help

https://support.industry.siemens.com/forum/nl/en/posts/modbus-tcp-error-818b/288740

I see that you are asking for 10 registers (DATA_LEN = 10). This will require storage space of at least 20 bytes. You have also chosen to start writing the data in DB address 12 of DB3 (P#DB3.DBX12.0). How big is DB3? What is the structure of DB3? I suspect that DB3 does not have enough space to hold the data.