If you are also going through any sort of InDesign errors, then primarily you must find out that whether only single file is affected or the entire folder of inDesign is damaged.
When you are confirmed that your file or document is damaged, then make use of below mentioned steps to retrieve your corrupted or lost data back:
1. Save as:
This is the very first technique you must try out to tackle your corrupted file. Using “Save as” selection since it compels InDesign to onslaught the structure of its directory. After storing it with the help of “Save as” option a file becomes comparatively small is size.
2. Content Export as an INX or IDML file and reopen that file
You can accumulate InDesign file in couple of supplementary formats: The file format of INX has been reachable because launching of the original CS version. The IDML format was included in CS4. In order to troubleshoot, export a file to INX or IDML and then try to reopen it again in InDesign.
3. Move all content to a new document:
You just do not have to COPY and PASTE personage frames to a whole new fresh file, as an alternative, InDesign facilitates you with an option using which you can shift whole page from one document to another.
If still you are not able to solve the issue with InDesign file then most preferable option would be to make use of some third part reliable software in order to fix corrupted InDesign documents and best choice for this is InDesign File Repair Tool. It recovers all elements including Text, layers, Tables, Images, Notes, Media Objects, Footnotes, Bookmarks, TOC, Cross-references, Hyperlinks, Special Characters, Standard Shapes, Animation and so on.

https://indd.filerepairtool.net/blog/troubleshooting-indesign-issues