PDF format is broken in Adobe Acrobat

Multiple PDF files I have created over the time using the same template are now all broken in Adobe Acrobat. The background is not showing anymore and I cannot edit them. The files are not broken because I can open them in Adobe Reader or in a browser without any issue. I attach a file with the problem. Please let me know what the issue might be , because I would not have expected such a killer bug. Thank you !