CAPI Error: -1007

I get this error every time 4.15 is launched. The projects open eventually but the loading slows to a crawl after this pops up around the 79% mark. Also happens when just launching 4.15 to create a project.

Did a couple searches and couldn’t find anything on it related to UE4.

Any suggestions would be helpful, really slows down the ol’ workflow.


Hi HaxO,

I could not find this specific error, however, from the CAPI Error Codes page:

  • 1001: Too many communications programs are using the CAPI driver. Close down the application you do not need.
  • 1008: Close down all applications and restart your PC.

-I’d imagine 1007 is memory related as well. Some users have experienced memory leaks with the editor and, in other cases, the user’s project is trying open to “infinite” loop.

To cancel out the latter, open a blank project and set it as the default map to open. Then restart the launcher and editor to open to the blank project. If the problem persists, it is not a problem with your project.

When the error occurs, also use the Task Manager to see what else, if anything, is running in the background. Close all other apps so that just UE4 is running.

If the problem is still occurring, try Verifying your installation; then delete the DerivedDataCache folder. Lastly, post your dxdiag and we will check to see if there is a known hardware conflict with your system.


For some reason, it appears your comment was deleted:

"This happens in any instance of 4.15 opening, whether it be a blank project, new project, or an old project that was ported to 4.15

There are usually a lot of programs running but this has never been an issue in the past as there is about 16gig of RAM in the machine

Installation has been verified, even delted 4.15 and re-downloaded it all together.

Will delete the DerivedDataCache when possible and update."

Let me know if deleting the Derived Data Cache resolves the issue. If not, please include your dxdiag with your response so that we can look for hardware conflicts.

I am having the same issue in 4.16 Preview. I did not have this issue in 4.15 and before. It always appears as 79% of the engine has loaded. This pauses loading until I click OK at which point the engine loads as usual.

Hi Monokkel,

After digging through some older posts about this error, here are few things to look for/try:

  • Do you have Oculus VR Runtime Service installed and running? If so, try ending the process, open the editor, and see if the issue still occurs.

  • Have you tried deleting the DerivedDataCache like mentioned above?

  • What drive is the engine installed on?

  • Could you provide your Dxdiag (system specs)?

Windows: Go to the Start menu and type ‘dxdiag’ into the search bar. Open the file and then click ‘Save All Information’. Post that text file here.

Mac: Go to the Apple menu and click ‘About This Mac’.