Hi, new to this. I am getting the same error. I developed a program in the WEB IDE, so I know it compiles, loads and runs. Copied and pasted that program to the Spark Dev on my Mac. Saved it in an empty folder with the .ino extension. It will not compile in Spark Dev. I get the App code was invalid error. Also tried saving the same code to another file with the .cpp extension, also in an empty folder by another name. Also tried quit Spark Dev, restart, open, and still get the error.
Is there some black magic to the folder layout? I’ve got a folder names SPARK in my Documents folder. Inside the SPARK folder are the two folders mentioned above, named TempLight1 and TempLight2. In those folders are the .ini, in 1 and the .cpp in 2.
I get the error and can make no progress. This has to be something simple. Can anyone suggest a solution? And, it probably should not be so hard to save a project in Spark Dev… hint hint.