Weird Issue Saving Project Files

OK, this is the strangest thing I’ve ever come across in 26 years of using Cubase.

I started a new project yesterday in Cubase Pro 10.5. I named it FFBQ and saved it in my Cubase project folder/sub-folder 1/sub-folder 2. It saved as a .cpr. No problem.

Today, I turned on the computer and went to open it Cubase and the new project. I started at the Hub, but noticed that the file was not listed on the list of recent projects. So I went to Open Other. I found the file, right where I left it, and next to it was a .bak file of the same project. Cubase told me that the backup file was newer, but I opted to open the .cpr file. Cubase then told me there was no such file, and showed me an empty folder. So I went to the folder location through Windows Explorer. I found my folder, but when I opened it, I found the .bak file with a Cubase 10.5 icon, and the .cpr file with a Cubase SX3 icon. (Yes, I do have SX3 installed for doing old-file conversions.) I attempted to open the .cpr file by double clicking. Again, Cubase showed me an empty folder. I tried to open the .bak file; Cubase showed me an empty folder. Attempting to open the files through the Cubase file menu results in the same thing.

So I started over from scratch with my project. I set it up with tracks and some time signature changes in the tempo track. I saved the file to the same folder. It again saved as a .cpr with the SX3 icon. I tried to open it by double-clicking. Windows asked if I wanted to open it with SX3. Instead, I chose C10.5. This time it opened.

I also see that, even though I have Auto Backups set for 12 minutes, with a max of 10 backup copies, I only have the one original .bak file, so it appears that my project is not getting backed up. This one .bak file also does not open in C10.5.

Anyone have any idea what’s happening here? I want Cubase to save my files as 10.5 .cprs, not SX3 .cprs. I also need to have my backup files working correctly. I can supply more details if needed. Thanks.

After I post this, I’m going to restart the computer again, and see what happens.


The application which opens any file type, is chosen by system (Windows). Right-click to the file, here (maybe in Properties?) you should be able to choose the application you want to use for the file type. Don’t forget to enable this for all files of this type, please.

If you haven’t seen your project in the Recent Projects, Cubase probably crashed while quit before.


I appreciate your input, but telling Windows what program to use to open the file does not change the icon, and it will try to open in SX3 again. However, I am now (magically) at least able to open the .cpr file normally from the file menu.


I’m sorry, Windows is not my first system. Maybe there are some registry to change to set up, which application should be used for which extension. But definitely this is on the system side. The system decides which application to call.

I hope this helps.

I never use the HUB. There has been a lot of discussion about this on the forum.

I open Cubase 10.5.2 so I just see the toolbar across the top, and then use the File > Open option to choose which project I want to work on. I have often had issues by just double-clicking the .cpr file in Explorer because I also have two Cubase versions on my computer - Cubase 8 Pro and Cubase 10.5.2.

I think Martin is correct about setting the default program in Windows but for some reason, that isn’t always reliable. Cubase doesn’t act like all other programs. It has specific rules that often vary from our conventional way of thinking.

Similarly, when closing a project it’s much faster to use File > Close, and then File > Quit, instead of the X in the upper right corner. Cubase is the only program I have ever used where this holds true. All other programs close with the same speed using the File options or X.