Hi, guys…I’ve gotten really depressed over this really fast. I’m working on a school project and making a game in blueprint. Foolishly I created a cpp file in the editor, and when I closed the editor, it gives me a message saying that modules were missing "Project.dll"and that I should rebuild from source. I have visual studio, but the thing is, I’m kinda new to Unreal, so I don’t know what all this fancy stuff mean when I look up solutions online. If anyone could help, I’d appreciate it. I’ll always be on standby for replies…
Open the “.sln” file inside your project folder to open Visual Studio. Then, above go to “Build -> Build Solution” and wait for it to finish. Shoud appear something like “Build: 1 succeeded, 0 failed, 0 up-to-date, 0 skipped” down below, in the “Output” panel
Where would I find this file? I looked throughout nearly my entire project and cannot find it…
If you can’t find it, right click on your “.uproject” file and click on “Generate Visual Studio project files” and it will appear. I thought it was already there since you’ve created a C++ class, but apparently not 
Mmmm…I did and I don’t think it did anything. I went ahead and searched by file extension (ext:sln) and nothing with that extension is in my projects folder.
Screenshot of the directory of files in your project folder after you Generated Visual Studio Project Files?
Is this what you’re talking about?
You guys??
After you hit “Generated Visual Studio Project Files” did something happen? A window appeared or something?
A progress bar appeared briefly, then disappeared.
I’d look into this issue then UE4.SLN not generated? -- Building from Source - General Discussion - Unreal Engine Forums
Yeah, like I had mentioned before, I don’t really know the specifics of all that quite yet, not until I start doing Unreal with C++ at least. I didn’t want to mess around with that stuff unless I knew exactly what I was doing. But anyways, thanks for all you guys’ help. I ended up just copying the Contents folder to a new project and everything is back to normal. All I had to do after was remap buttons in the input manager and change some editor preferences back to what they were.
Delete the Intermediate and Config folders only. Try open your project again.
PS: You probably will need to make changes to the Project Settings if you were using any external asset. Experiment deleting only the Intermediate 1st.
Yeah, that didn’t quite work either. I didn’t know attempting to make a c++ file would be this damaging…
You can create a new project of same type and copy everything under Content Folder from the old project to the new project.
Yeah, I ended up doing that, thank goodness that didn’t cause too much trouble
A bit of thread necro here, but this really helped me! For some reason I was never even getting the “Generate Visual Studio Project Files” so couldn’t try that, and deleting the Intermediate and Config folders didn’t help at all.
Thanks a lot, this was frustrating as hell, and I still don’t know what caused the issue in the first place!