Kindle conversion to PDF results in garbage

[jgt1942]

Normally I do not use the Kindle app on my windows PC but recently I purchased several books (21) via Amazon that are about the Ornish diet. The version on the PC is 1.17.1 (44183). Normally after I download a Kindle book I copy it to Calibre (5.33) and access it through Calibre. Once in Kindle, I often convert it to a PDF or another ePub format.

Two of the books when converted result in garbage such as this:

%MOP<ìúYüEyT u™= yÖ& |üÖ ƒÒ OE_ú ”Y‚ ›Û £ÝL ¬)b ²‹w ¸K ½M¹
Á) Ç/Î Îý ×|I ßÅÎ æ“ß ìrÌ ó>Ä û“•ÿ ”öŠ_éu^øV¤&ú§*¡`1Q6RÇ:

• THE ORNISH DIET COOKBOOK FOR DUMMIES: SEVERAL HEALTHY ORNISH DIET RECIPES INCLUDING MEAL PLAN, FOOD LIST TO REVERSE HEART DISEASE AND OVERALL BODY HEALTH
• 2021 ORNISH DIET: Quick and Easy Ornish Diet Recipes Including Meal Plan , Food List And Getting Started

Any suggestions?

[jhowell]

The %MOP indicates that the book is actually a PDF encapsulated in MOBI format.

Here is a recent thread about someone else experiencing the same problem: Could not find reasonable point at which to split.