S7 - Shared DB from Mulit Instance?

What should I be aware of when trying to open a shared DB from an multiple instance FB.

The code below doesn't work in a multi instance FB.

OPN #DB_PARAM
L DBNO
T #Param_DBNo

Hope this makes sense....

Does the plc report any erros in the diagnostic buffer ?
What values are in the accumulator/db register when you monitor the code ?

False alarm.

I apologies it was only a compilation conflict that was my issue. Somehow my PC's date/time has been reset. I have run antivirus and it has come up negative. I have been simiulating WinCC with PLCSim could this of done this?