Please be advised that some users are experiencing an issue with the latest version of Guides if you have updated to the latest Guides CDS Solution (version 400.0.4.31) and Guides PC/HL applications (version 404.2008.19001.0).
This issue results in an incorrect error message that states a guide is corrupted and cannot be opened.
This issue is localized to the specific device and the guide is in fact not corrupted.
We are working on a fix for immediate release but in the meantime please follow the below steps to resolve. We will post in the replies to this thread when the fix is released.
On PC please follow these steps:
1) Go to Windows settings
2) Select Apps
3) Search for "Guides"
4) Select Dynamics 365 Guides
5) Select advanced options
6) Select the reset button