As mentioned above, that you are willing to combine more than 12 pdf files. As using PDF Pack you have maximum number of file limit 12 to combine files.
What you can do to increase the number is combine 12 files together and save and then add other files to that combined file (already created using 12 files). This way you can maintain the number of files limit.
Thank goodness I found this, you saved me from a meltdown!
Glad to hear that helped you.
Use Nuance PowerPDF that can combine over 100 pdf files in one operation twithout a problem.
I see they answered your question. It’s shameful to pay so much for Adobe when it is so limited in its use, not to mention not exactly user freindly.
PDF Pack has this limitation, it's not considered expensive. If you want to remove the limit you need Acrobat Standard or Acrobat Pro. This runs locally instead of sending files to Adobe.