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Windows Service for Excel File Inspecting throws License errors after upgrade from Aspose.Cells for .NET 4.1.1 to 7.1.2

Hi All,

We've been using a licensed copy of Aspose Cells 4.1.1 in several of our COM+ Dlls and some Windows Services since 2006.

Last April we purchased the Cells for .NET 7.1.2 upgrade and released this packaged with our other software as part of an update/patch.

However, one windows service keeps getting this error [Aspose.Cells.CellsException: You are using an evaluation copy and have opened files exceeding limitation.].
This service only uses Aspose.Cells.Workbook one stored procedure to perform an ExportDataTableAsString operation. Nothing else.

After lookng thorugh the forums, we believe we might be missing a call to SetLicense as described in your FAQs. We do call SetLicense in our other COM+ Dlls but we never needed to call it withing this Windows service.

Is this the solution for our issue and if it is, why do we need to do this all of a sudden while it was fine opening and exporting files before?

I've attached screencaps of the only lines wherein this windows service uses Aspose.Cells. We had to make these "AFTER" changes after we upgraded to 7.1.2 .NET.

We'd appreciate any input you have regarding the matter.




Thanks for your posting and using Aspose.Cells for .NET.

This error occurs when Aspose.Cells is used in Evaluation Mode. If you will set a license, this problem will disappear.

Please check the following document for your further reference.

The limitations are shown below:

1st Limitation: Number of Opened Files – Aspose.Cells

When running your program, you can only open 100 Excel files using Aspose.Cells library. If your application exceeds this number, an exception will be thrown.

Hi mshakeel,

Thanks for that. I understand that may be the case.

My question is mainly regarding "Why do we need to do this all of a sudden?" because the Windows service in questions has been released to clients for years without having the "setlicense" procedure called anywhere in the code.

We use the set license procedure in other projects but never encountered the need in this service. Why do we need to call it now when it's been running fine until we upgraded from 4.1.1 to 7.1.2?

Is this 100 Excel File Limitation a "new" feature in Aspose Cells 7 that wasnt there in 4?


Thanks for your posting and using Aspose.Cells.

Please check your License Expiry Date. You can check it by opening your license in a notepad.

If your license has expired, then this may also cause this issue.

Please also send us your license so that we could further look into this issue. You can send us your license by following the steps mentioned in this article.

Here's the expiry:


So my question still stands. Can we just please know if the 100 Excel File opening limitation is a new feature in Aspose Cells 7.1.2 and wasn't a limitation in our old 4.1.1?

I'm asking this because the windows service we have that has been using Aspose Cells for years *never* called SetLicense but did not encounter this limitation until we upgraded.


Thanks for checking the License Expiry date.

I guess this check has been added later on and did not exist in the earlier versions, that’s why earlier versions were working fine.