suddenly I don't open mpp files

Brass Contributor

Hello All,

I'm using MS Project 2016 and I saved a file several times. Now, I cannot open the file in MS project.

Could You help me how I can repair it?


15 Replies


Do you get an error message?

Can you create a new Project file? If so, can you save that and then re-open it?

Did you save your original file to your local drive or to a remote server?



Hello John @John-project ,

 No error message!

I saved the file normally two days ago and now if I try to open it nothing appears. Only the MS project tool remain open.

I can create and open different project files saved and reopen them


Likely the issue is in the specified file. There is a way to repair it?

thanks a lot for your prompt answer



You say you saved it "normally" but didn't say where (i.e. locally or to a remote server). Saving remotely can result in corruption if there is any glitch on the network during the save process.

If you are able to create, save and re-open a new file, it appears Project is working okay so as you suspect, the problem is with your file itself. I suggest you try methods 1 and 3 in the following Wiki article: 


If the above methods do not help, you could search the internet for third party applications that claim to recover damaged Project files. I know some do exist but I have no personal experience about how well they work.


As an alternate, You'll have to search for the last saved backup that will open and go from there. If you have no such backup, I'm afraid the your only option is to start over. Note, if you happened to send your file to someone, perhaps you can retrieve that as a "backup".




Hello John,
I saved locally.
Method 1 and 2 cannot apply because I cannot open the file.
I tried the method 3 but did not work : no chance to expand the subproject (my file) in all tasks.
In case You would like investigate I can provide the file.

Sure I'll take a look but if you can't open the file, there is a very high probability I won't be able to either, but, it won't cost you anything to try. Send it to me at the address below.
(remove obvious redundancies)
hello John,
best response confirmed by demetrio61 (Brass Contributor)
To those following this thread,
Demetrio sent me his file and as expected I got a "problem with this file" error message when I attempted to open it. I was able to open it read only and could see resources on the Resource Sheet but a task count showed zero tasks.

If someone else has any ideas please jump in.
First of all, I would like to thank John for the time.
It seems no solution for the issue. Therefore I must forget the file and repeat my work.
Thanks a lot
I investigated 5 minutes in internet and found someone who claims they can repair the file for a fee.
My observation that I would like to share with everyone: it is very likely (to be verified) that there is a way to repair this file. There are conditions to involve some Microsoft Project developers in the discussion.
I start from the idea that if there is a way to repair a file they know it.
Perhaps this community is missing an "on-demand link" with the MS project developers.
Is my reasoning correct?
demetrio61 --

No, I think your reasoning is not correct. I doubt the corrupted file can be repaired, but if you want to pay someone to repair it, give them your money and hope for the best. And if they are able to repair your corrupted file, please let us know.

Also, Microsoft will never add an "on demand" link in this user forum. After working with Microsoft products for many years, I can assure you that Microsoft DOES NOT provide free support and they WILL NOT give you direct access to their software developers. If you want free help, this user forum is staffed by volunteers such as myself. Otherwise, you can open a support ticket with Microsoft Support, and pay for the help.

Hope this helps.
First of all I thank Dale for taking the time.
I have just opened an internal ticket to my ICT in order to see if it can resolve the issue possibly with the support of Microsoft. In case this fails I will redevelop the project again.
demetrio61 --

Microsoft Project has a feature that will automatically make a backup copy of your project when you save it. If you are able to get the project repaired, then open it and try the following:

1. Click File > Save As and then click the Browse button on the Save As page.
2. At the bottom of the Save As dialog, click the Tools pick list button.
3. On the Tools menu, click the General Options item.
4. In the Save Options dialog, select the Always Create Backup option, and then click the OK button.
5. Click the Save button.
6. If prompted to overwrite the existing project, click the Yes button.

After completing the above steps, Microsoft Project will automatically create a backup file of the project file in the same folder as the project file. The backup file has the same name as the project, except with the file extension .BAK. The software will update the backup file every time you save your project, so that you always have a current copy of the project information in the backup file.

If you ever need to revert to the backup file, you will need to click File > Open > Browse and then navigate to the folder containing the backup files. In the Open dialog, In the lower right corner of the Open dialog, click the file type pick list (it displays Projects (*.mpp) as the default file type), and select the All Files (*.*) option. You will now see the backup project, so that you can select it and open it.

Even if you are not able to repair the corrupted project and need to create it again from scratch, you will still be able to create a backup of it using the preceding steps. Hope this helps.
Hi Dave,
considering that I don't trust ICT very much, since yesterday I have redeveloped the project again. I just finished after two days of hard work. I just followed your great backup tip right now.
Anyway, out of curiosity I want to see if ICT can repair the previous file.
Thanks a lot


Hello All,
I just have again the issue on a different project. On Yesterday, I introduced change in my previous file ( March 2021) and now I can not open it. I noticed that if I open the file with Project 2013 viewer appear the following message:
MPPFile.Reprocess MPPFile.process: switch (format) (type=14):
Number was less than the array's lower bound in the first dimension.
Parameter name: srcindex

Stack trace:
at Housatonic.HPV7.Mpp.MPPFile.Reprocess ()
at Housatonic.HPV_Solo.MainSolo.FileOpen (string fileName, String password)

Thanks in advance

Hello All, 

I finally solved:

after several attempts, I tried to open the corrupt file with a different PC and with a different Ms project (Project on line). I managed to open it, save it with a different name and then reopen it and edit it on my PC with my 2016 project.

Then, I can say:

They are the Mysteries of Microsoft !!!!!!!!