how to contact support ????
Sorry for the delay in response to the you query.
When you try to convert the file, what exactly happen? Do you get any error message, that's related to the "Conversion Failure"?
If it is an activation issue then, you may follow the steps mentioned below, to activate the subscription.
1- Export PDF is an online service that you can use online via: https://cloud.acrobat.com/exportpdf
2- You can also use the services through free desktop version of Adobe Acrobat Reader DC: Adobe Acrobat Reader DC Install for all versions
3- “Sign In” using the email (Adobe ID) under which you have subscription registered.
4- For detailed description of how to use the Export PDF service, you may refer to- Using Adobe Export PDF
You may refer to the following link for any troubleshooting: Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud...
Let us know if it still doesn't work.