Can't recover trashed 358-page InDesign CC 2017 document

but somehow I trashed my 358-page InDesign CC 2017 document, and no way could find out how to recover it.

There are a number of file recovery apps out there some are free. I've used Stellar Recovery and it works great. It's not free, but the demo will tell you if the trashed file is still there.

Data Recovery Software Free Download – Stellar Data Recovery

The sooner you run a file recovery utility after the loss the better the chance of recovering trashed files.

What many of us who have used technology over the years have learned is the maxim “save and backup early and often” even if it appears somewhat inconvenient. This applies not only to InDesign documents, but virtually any type of digital asset that is being worked on for a period of time with numerous edit cycles including spreadsheets, photos, presentations, etc.

In my own work using InDesign, it is not unusual for me to work for an hour, save (using “save as”) the document, close the document, copy the document to a backup location with a “generation name,” and then reopen the document in InDesign. (If you are particularly concerned about document integrity, you might also do a IDML save as well!) I do the same thing when doing complex image edits and spreadsheet edits. It may seem like paranoia, but it has saved my tuchas many times.       

          - Dov

Is your file corrupted? That is do you have it but it won't open? In that case Markzware's product is the place to go.

But if you put your file in the trash (or recycle bin) and then emptied them, you need a hard disk recovery service. And even then you may not get much. Especially if you've been writing on and off of the hard disk.

Are you sure you trashed it? Or maybe it's sitting in the trash but it wasn't emptied.

Markzware has a file recovery service you can pay for:

DTP File Recovery Service | Markzware