Hello,
We had fixed the error "Object reference not set to an instance of an object". Please download spire.doc_hotfix_4.5.3 from the link http://www.e-iceblue.com/downloads/hot_fix/spire.doc_hotfix_4.5.35.zip.
Please try to use it to test all problems you encountered. If you still have previous problems, please tell us and provide us your complete project which we can directly run on our side. So that we can reproduce the problems soon. Thank you!
Best regards,
Amy
E-iceblue support team