We’re unable to form fill this pdf using version 4.3. Can you let us know what could be causing this to fail?
Thank you for sharing the template file.
First of all, let me inform you that Aspose.Pdf for .NET and Aspose.Pdf.Kit for .NET have been merged into a single product and Aspose.Pdf.Kit for .NET has been discontinued as a separate product. All the features of Aspose.Pdf.Kit for .NET are available under Aspose.Pdf.Facades namespace of Aspose.Pdf for .NET v6.x. You can check the following documentation links to upgrade your code from Aspose.Pdf.Kit for .NET to the new merged Aspose.Pdf for .NET.
Also, I checked your template file with the latest version of Aspose.Pdf for .NET v6.7 and I am able to fill the form fields. You can download and try the latest version of Aspose.Pdf for .NET and see if your still face any issue.
Please feel free to contact support in case you need any further assistance.
Thank You & Best Regards,