Looking at the information shared above it seems that you are experiencing this trouble with the specific pdf? There are couple of possibilities that the next pdf is giving blank page to you-
1- The original pdf that you are converting as a Excel, does it contain real text in it? if not, then that might cause issue with conversion.
2- If the original pdf is a scanned pdf or contain only images in it then the converted Excel might not give the appropriate result.
3- If you are trying the conversion online through- https://cloud.acrobat.com/exportpdf then you may check with a different web browser or clear cache and cookies of the current one.
4- Check with the Adobe Reader DC desktop application- Adobe - Adobe Acrobat Reader DC Distribution if its already there then make sure it has all the latest updates installed.