This particular error message occurs due to certain content within the word document being corrupt.

• This can be caused due to copy pasting content within the word document. We recommend to paste the content as plain text- Ctrl+Shift+V

In order to resolve the issue you could try these steps:

Open the particular report> File>info>Check for issues>inspect the document>Inspect>Document properties and personal information>remove all

Step 1:

If that does not help, alternate troubleshooting would be to repair the word document by following steps within the article

https://support.microsoft.com/en-us/office/open-a-document-after-a-file-corruption-error-47df9d48-2165-4411-a699-1786ac734bc3

1. Click File > Open > Browse and then go to the location or folder where the document (Word), workbook (Excel), or presentation (PowerPoint) is stored. ...
2. Click the file you want, and then click the arrow next to Open, and click Open and Repair.

Note- Save the Repaired version of the word document locally within your system.

• Within Report manager> draft>locate the report >edit properties>and upload the repaired word document as new version of the report 

• To edit the report’s details, in the same report drop down menu click on Edit Properties.

• To upload a new version and replace the existing report, click on Upload new version, at the top of the page, under file name.
• This should fix the issue and you should be then able to open the report document without any issues