There are some JSON formatters online, but I don't know how much damage they can handle.

A fallback plan might be to extract all the URLs from the file (without the structure, tags, date added, last visited, etc.).

Just in case... could you check whether Windows created the C:\Windows.old\ folder? That might not be applicable to the way you reinstalled, but if you have it, likely there are valid backup files in there.

Thank you for promptness. Unfortunately, I didn't find this folder called Windows.old. I have formatted as I said the partition C. If there is a solution to repair that json file and if you know you can tell me how to do that. Or, to extract all the websites from the json file. This is the last solution to extract all websites in case that can not be done anything.

You can open the file in the Scratchpad (Firefox/Tools > Web Developer) and click the "Pretty Print" button to see if that allows to find the position where the error occurs.

No chance. I opened the file json, but it remain the same the window with this text in scratcherpad. /*

* This is a JavaScript Scratchpad.
*
* Enter some JavaScript, then Right Click or choose from the Execute Menu:
* 1. Run to evaluate the selected text (Ctrl+R),
* 2. Inspect to bring up an Object Inspector on the result (Ctrl+I), or,
* 3. Display to insert the result in a comment after the selection. (Ctrl+L)
*/

Hi gaddy, if you change the file type drop-down in the Scratchpad's Open File dialog, can you open text files or other types of files in the Scratchpad? In other words, is the problem limited to that one JSON file?