What is causing conversion failure on one pdf document I want to combine?

Hello charlesw72229390

We apologize for the inconvenience caused, as per the description above, you are not able to combine PDF files as getting conversion failure error, Is that correct?

The record shows that you have an active subscription of Adobe PDFPack on your current Adobe ID, please try to combine files using the URL https://cloud.acrobat.com/combinepdf  on a different browser like Chrome, or Firefox, or Safari and check if it brings any difference.

You may also refer to the following KB docs and try the troubleshooting steps: File conversion error when combining files

Conversion Failure while combining files

PDF Pack combine files doesn't work, conversion failure

For more troubleshooting, you may also refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud Services).

Hope this helps and let us know how it goes.

Regards,

Anand Sri.