An Outlook PST is prone to corruption reasons such as unexpected shutdown, 2 GB file size limitation, network sharing, virus attack, and similar others. To solve such, though not all, problems, Microsoft provides a built-in Outlook tool called Inbox Repair Tool. The tool is associated with a program file-'Scanpst.exe'. This utility is designed to examine the structure of corrupted PST file and hence, repair it. But due to several limitations, Scanpst may fail to fix the damaged PST. These can be because the file is oversized, file installation is incomplete, and due to several other causes.
Scanpst tool can fail in number of cases. One of such examples is when you find an Outlook PST corrupted, run the Inbox Repair Tool, but the tool freezes with no result. The tool may find the problems correctly, but hangs when you hit to repair the file. Trying to run the tool in Safe mode also fails.
Some possible reasons behind such issue are:
(1) The Inbox Repair Tool is not updated or not installed properly.
(2) You are trying to repair a PST, which is above 2 GB. The Inbox Repair Tool cannot repair PST that is more than 2 GB in size.
(3) The tool finds errors that it cannot repair.
You can try implementing these suggestions to solve the existing issue:
(1) Download and install all the recent updates available for Outlook. Reinstall Outlook as the last option.
(2) Check the PST file size. If it is above 2 GB, you can use 2 GB truncation utility. Make sure you backup the file first as this tool truncates the file up to the specified size value and can cause important data to delete. Re-run the Scanpst tool.
(3) If you can open the affected PST, create a new PST and import all items to this.
(4) In case you cannot access the file, you are suggested to use a third-party PST file repair utility. These tools can Scan PST file using powerful and safe algorithms and can be used in each instance of corruption, even the 2 GB problem.