Have a corrupted file in InDesign C5.5,

I'd be willing to take a stab at it if you want to share the file here.

Are you a Windows user? If so, you can try the blind-open recovery tool that can be downloaded from Kasyan's site: INDDRecovery — a program for restoring corrupted InDesign documents 

The first problem, and maybe all of it, is that CS5.5 is really, really obsolete even if it's running on an original OS and platform. Many things have changed outside the software itself and it may simply not run any more without glitches.

That said, there's a fairly universal fix for file corruption in InDesign. Save the file (or export it — it varies with the specific software revision) to IDML format, then reopen it as an INDD file.

I can't say for sure where this option might be. In current versions, you can both "Save As" IDML and "Export" to the format. CS5.5 might have either or both.

And the other fix is to always save archive copies of work, after each major addition or change if not daily. Doing a lot of work with only one file that can get damaged or deleted is walking a tightrope. Save, save, save to a continuing series of back up copies.

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