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error when importing a DLL - 'An attempt was made to load a program with an incorrect format. '

Level 3


I have the following error message when I try to import a DLL in Blue Prism :

"Metadata file 'c:\Program Files\Blue Prism Limited\Blue Prism Automate\*****.dll' could not be opened -- 'An attempt was made to load a program with an incorrect format. ''"

I copied the DLL in C:\Program Files\Blue Prism Limited\Blue Prism Automate and I imported in Code Options > External References in the Initialise page of the VBO. After that I reboot Blue Prism (close and reopen BP).

Can you help me, please?



Hi @leogarp ,


If you can provide us with screenshot of the what you have mentioned under the External References tab and show us where it has been pasted, that would help a bit more. 


Also, please provide us with the name of the DLL and let us know if that's an officially available DLL from Nuget or something internally built within your team.

Hope this helps you out and if so, please mark the current thread as the 'Answer', so others can refer to the same for reference in future.
Devneet Mohanty,
SS&C Blueprism Community MVP 2024,
Automation Architect,
Wonderbotz India Pvt. Ltd.

Hi @devneetmohanty07 ,

The problem is for the last 2 DLL, I mentionned their path in the External References.

I put the DLL in the Blue Prism folder.


I don't know if the DLL is an officially available DLL from Nuget but they come from a proprietary software. So I can't give you the name of the DLL for now, sorry.

Best regards,