All of a sudden, when I try to build my Arduino project in VS2017, I receive an error (see below).  As far as I know, nothing has changed.   

System.Exception: Build folder disappeared, could not be written or there was an internal problem combining pde/ino files
OR
Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index ---> System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
   at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
   at System.Collections.Generic.List`1.get_Item(Int32 index)
   at Visual.Micro.MiroAppAPI.PdePreprocessor.getPrototypes(String sIn)
   at Visual.Micro.MiroAppAPI.PdePreprocessor.writePrefix(String program, String BuildPath, String SketchName, String[] codeFolderPackages, String morePrefix, Boolean autoGenPrototypes, Boolean alwaysUseRegExToFindIncludes)
   at Visual.Micro.MiroAppAPI.SketchBuilder.preprocess(String buildPath, PdePreprocessor preprocessor, Boolean PreProcessOnly)
   --- End of inner exception stack trace ---
   at Visual.Micro.MiroAppAPI.SketchBuilder.preprocess(String buildPath, PdePreprocessor preprocessor, Boolean PreProcessOnly)
   at Visual.Micro.MiroAppAPI.SketchBuilder.preprocess(String buildPath, Boolean PreProcessOnly)
   at Visual.Micro.MiroAppAPI.SketchCompilerArduino.TryRunCTags(Board brd, List`1 includePaths, SketchLibraryListUnSorted knownLibs)
   at Visual.Micro.MiroAppAPI.SketchCompilerArduino._compile(SketchBuilder lsketch, String primaryClassName, Boolean verbose, Boolean isDebug)
   at Visual.Micro.MiroAppAPI.SketchCompilerArduino.compile(SketchBuilder lsketch, String primaryClassName, Boolean verbose, Boolean isDebug)
   at Visual.Micro.Visual.Studio.Arduino.AddInApp._CompileDo(Object oProject, Boolean IsDebugStartCommand, Boolean isRebuild, Boolean UseGdbIfAvailable)
   at Visual.Micro.Visual.Studio.Arduino.AddInApp.CompileDo(Object oProject, Boolean IsDebugStartCommand, Boolean isRebuild, Boolean UseGdbIfAvailable)
   at Visual.Micro.Visual.Studio.Arduino.AddInApp.Compile(Object oProject, Boolean IsDebugStartCommand, Boolean IsRebuild, Boolean UseGdbIfAvailable)

I will send a full copy of the log via email as there is plenty of sensitive information in that log file. 

Things I have tried so far:

- upgrading VS 2017 to the latest version
- uninstalled Visual Micro and reinstalled it
- running VS in administrator mode

There are no program code errors and as far as I can tell, I can access the output folder in windows explorer.

I was about to try VS2019 but before I start installing it, I was hoping someone has seen this before.

Thanks in advance.

Thanks for the email but it is missing the build properties. You have to enable both "show build properties" and "verbose"

Also easier in a .txt file.

Thanks

Thank you for the quick response.  I will email the ino file as requested.   

Will the ino file be sufficient or do you also need the C++ classes as well?  What about the libraries?

Reviewing the sketch, there are prototypes defined for Setup() and Loop() around line 236.

Can you try commenting these out and re-building to see if it resolves the error?

We will continue to investigate the root cause of the problem and will update when we have more information around this.

I have installed the latest release as per your link.  VS shows version 2020.518.4.

When I try to build I am still receiving the same message.  I have sent an email with the full log.

Thanks again.

Yes no problem as long as all copies of the files are removed from your system(s) when testing is complete.

I will prepare the code files for you shortly and email them.

Unfortunately still no luck.  Also, I didn't notice any discrepancies in the two prototypes mentioned earlier.

I am happy to diagnosis the issue farther however I am in desperate need to compile and release an update to my software.  What version can I downgrade to in the meantime so that I can compile again?  I am not sure what version the problem was introduced in?

I am happy to upgrade again in a week or so to continue testing.

An alternative to downgrading should be to turn off this component:

• Right Click Project > Add > Local Board.txt
• Add the below entry to the file, save
  
  Code

  

  vm.ctags=false 
  
  

• Rebuild project

The discrepancies mentioned are only due to how we have to match up the declaration to the definition, so if they do not match exactly (all parameter names etc) we may inject additional/incorrect prototypes.

Here we would generate another prototype for myFunction as "void myFunction(int)" <> "void myFunction(int paramOne)", and to avoid this both should be with "paramOne" present.

void myFunction(int);
void myFunction(int paramOne) { }
 

Did you ever find what was causing this?

I was getting the same error which was driving me crazy for a couple of days but when I switched on Verbose it stopped?

I'm a bit worried it's going to come back again so if there's any tips to avoid it this'd be great

Cheers