Hello All,

I'm posting this for anyone else that comes across this so they don't have to spend days trying to debug it.

The full error is:
Build validation failed for sketch 'ABC': Illegal characters in path. Ide=Arduino 1.6/1.8

If you get this when trying to just save a file in a project (any file), or trying to compile doesn't even really start and returns this error straight way, I have a possible cause for you.

For me, I had two double quotes around an include.
include "ir.h""    instead of    include "ir.h"

Yes it messed up code everywhere, but this was really time consuming to find. There are some old threads about looking at the Arduino IDE configured path, I looked at that, some registry keys, I looked at that, resetting the environment, recreating the project, generating debug files... I did a lot to try and find this.

So, if you get this error, check all your includes don't have an extra double quote as the error message doesn't help you find this at all.

Learn from my pain... Enjoy.

Hello,

It's pretty easy to duplicate. Just add an addtional " to an include:
#include "ir.h""
and it'll break.

Nothing complains about the extra double quote.
Just an error saving, and an instance fail when trying to compile.
Included build info as requested.
Everything is default. I'm not using any specical compilier flags etc.


Example, build instance fail:
System.ArgumentException: Illegal characters in path.
   at System.IO.Path.CheckInvalidPathChars(String path, Boolean checkAdditional)
   at System.IO.Path.InternalCombine(String path1, String path2)
   at System.IO.FileSystemEnumerableIterator`1.GetFullSearchString(String fullPath, String searchPattern)
   at System.IO.FileSystemEnumerableIterator`1..ctor(String path, String originalUserPath, String searchPattern, SearchOption searchOption, SearchResultHandler`1 resultHandler, Boolean checkHost)
   at System.IO.DirectoryInfo.InternalGetFiles(String searchPattern, SearchOption searchOption)
   at Visual.Micro.MiroAppAPI.SketchLibrary.ContainsHeader(String headerName)
   at Visual.Micro.MiroAppAPI.MCUTargetPlatform.getImportedLibsOfSketch(List`1 importedSketchHeaders, Boolean canCache, SketchLibraryListUnSorted local_library_lookup_list)
   at Visual.Micro.MiroAppAPI.MCUTargetPlatform.getImportedLibsOfSketch(List`1 importedSketchHeaders)
   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.SketchBuilder._build(String lbuildPath, Boolean verbose, Boolean PreProcessOnly)
   at Visual.Micro.MiroAppAPI.SketchBuilder._build(Boolean verbose)
   at Visual.Micro.MiroAppAPI.SketchBuilder.build(Boolean verbose)
   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.OnBeforeCommandEvent(String sGuid, Int32 ID, Object CustomIn, Object CustomOut, Boolean& CancelDefault)

We have improved the error message to show the #include which is at fault when this error occurs in the latest version (25.0120.0), which can be installed from the top of the below board:
https://www.visualmicro.com/forums/YaBB.pl?board=VS_ARDUINO_EXT_RELEASES