Thank you for contacting us.
There aren't reports about issues in the cloud services for the time of your writing. Further, from the error message, I see that the server files of your project have been locked. This normally happens if you, for example execute second cloud build without waiting the first one to finish in Visual Studio. This workflow locks your project on the server and leads to the above mentioned error. If this is indeed the case, the matter should be fixed as soon as the initial build process finishes.
However, if you are still experiencing the issue, I will require a Fiddler trace about it. Please, share such in a separate support ticket as it could contain sensitive information about your Telerik Platform account. Here are the steps you will need to perform:
1. Download Fiddler from here and install it.
2. Run Fiddler and go to Tools -> Fiddler Options.
3. On the HTTPS page, verify that Capture HTTPS Connects is enabled.
4. Verify that Decrypt HTTPS traffic is enabled with the ...from all processes option and minimize Fiddler to tray.
5. Try to build your application. When it fails, continue to step 6.
6. Open Fiddler again, go to File -> Save -> All Sessions, save the archive to disk (a SAZ file).
7. Finally, send us the saz files attached to your support ticket.
I hope this helps.