Spire.Doc 8.12.14 & Spire.PDF 12.9.18 compatability

[otechadmin]

Hello Team,
We have been using Spire.Doc 8.12.14 for quite some time without any issues. Recently, we purchased Spire.PDF, and it appears there may be a compatibility issue when adding the latest version of Spire.PDF to our project.

We are encountering the following exception:

'Could not load type 'spr᝘' from assembly 'Spire.Doc, Version=8.12.14.0, Culture=neutral, PublicKeyToken=663f351905198cb3' because it attempts to implement a class as an interface.'

We also tried upgrading to different newer versions of Spire.Doc, but those versions display the evaluation warning message, which suggests that our current license may not cover them.

Could you please advise:

1. Which version of Spire.Doc is compatible with the latest version of Spire.PDF?
2. Is there a specific version combination that you recommend for licensed use without compatibility issues?
3. Are there any additional steps required to resolve this assembly conflict?

Thank you for your assistance.

[Lisa.Li]

Hello,

Thank you for your inquiry,
Because product architecture has been adjusted, the old Spire.Doc 8.12.14 and the latest Spire.PDF 12.9.18 are indeed incompatible. To use it with the latest Spire.PDF 12.9.18, you must use a newer version of our Spire.Doc (the latest is currently 14.9.11) and need to renew a new license subscription to use the most recent version of Spire.Doc Pro Edition V14.9.11.
If ther is any other questions, just feel free to write back.

Sincerely,
Lisa
E-iceblue support team