1. Go into properties and select Show unread.
2. Try to change the view.
3. If it doesn’t change anything, then it will have to recover the .pst file.
I think you have a problem with exceeding the memory limit. If you don’t know much about the program, it is easiest to use for thisspecial program that will be able to do all the work for you. There are many different programs for this in the Internet paid and free. You can search Google to find them without a problem. I personally use outlook pst repair tool like PST Repair Kit. I have used it more than once and it always did its job. There is a demo version on the website so that you can check your file and see whether to buy this program or not.
You mean this tool? http://www.outlookpst.repair/