Aspose can't open up file with External DDE links?


Hi. I am getting an error (“Key cannot be null.”) trying to use Aspose to open up an Excel file that contains External DDE links. Here is a stack trace into the obfuscated Aspose code:

ArgumentNullException? : Key cannot be null. Parameter name: key at ?.?.?(MemoryStream? ?) at ?.?.?(String ?) at Aspose.Excel.Excel.Open(String fileName)

you can easily reproduce this error by just creating a new Excel file and adding a cell that has the formula


and saving. When opening up this file from Excel, it asks you if you want to update links. Regular Excel automation has a parameter on the Open to tell you whether you want to update the links or not. Obviously Aspose will not be able to update the links; however, I need to be able to:
a) open up an Excel file from Aspose that contains the DDE links

and ideally:

b) read the previous result of the link that was written to the cell.

any idea on how I can at least open up the file without getting an error? I have also attached an Excel file that I generated that will cause the same error. Thanks in advance.



Hi Bob,

Aspose.Excel doesn’t support external DDE links now. We will add this feature in the future release. It will be available within 2-4 weeks.

Your request a will be served in the future release but b is too difficult to implement.

I don’t find you attached file. Could you please post it here again? That will help us to implement this feature. Thank you.



Thanks so much for your quick reply! I will see if I can get the original file reposted. It is very difficult for me because we don’t have web access (we only have a public internet terminal) and I had to jump through hoops to get the original file to the terminal in the first place (I wish you still had email support).

The file I generated was a simple file that I created through the instructions in my original post (just creating a new Excel file with a cell containing the formula I provided). The cell didn’t even have a valid, previously downloaded DDE value (e.g., it just said #REF! in the cell if you look at it). If you give me an email address, I can email the file to you.

I still don’t understand exactly what feature you say you are going to support. Are you going to just allow aspose to not crash if you open up a file that contains any DDE links in it, or are you going to allow reading the value that was previously saved to the DDE cell? I know you are not going to actually connect to the DDE server to retrieve the value, as that would be very difficult for you to write.

Thanks again,


Hi Bob,

Please send your file to Thanks.

In the future release Aspose.Excel will open files with DDE links without any problem but it cannot retrieve values from the DDE links.