# Cannot build plugin host **URL:** \ **Category:** General JUCE discussion\ **Created:** [October 6, 2017, 5:03pm UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539 "2017-10-06T17:03:39Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![wub](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/wub/32/2908_2.png) [@wub](https://forum.juce.com/u/wub)\ **Post date:** [October 6, 2017, 5:03pm UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/1 "2017-10-06T17:03:39Z")
I tried to build the Plugin Host example and got the following: Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol “public: virtual \_\_cdecl Steinberg::FLock::~FLock(void)” (??1FLock@Steinberg@@UEAA@XZ) referenced in function “public: virtual \_\_cdecl Steinberg::UpdateHandler::~UpdateHandler(void)” (??1UpdateHandler@Steinberg@@UEAA@XZ) Plugin Host\_App C:\Users\profw\Documents\newJUCE\JUCE\examples\audio plugin host\Builds\VisualStudio2017\include\_juce\_audio\_processors.obj 1 Error LNK2019 unresolved external symbol “public: \_\_cdecl Steinberg::FLock::FLock(char const \*)” (??0FLock@Steinberg@@QEAA@PEBD@Z) referenced in function “void \_\_cdecl Steinberg::Singleton::lockRegister(void)” (?lockRegister@Singleton@Steinberg@@YAXXZ) Plugin Host\_App C:\Users\profw\Documents\newJUCE\JUCE\examples\audio plugin host\Builds\VisualStudio2017\include\_juce\_audio\_processors.obj 1 Error LNK1120 2 unresolved externals Plugin Host\_App C:\Users\profw\Documents\newJUCE\JUCE\examples\audio plugin host\Builds\VisualStudio2017\x64\Debug\App\Plugin Host.exe 1 I’m using Visual Studio 2017 on Windows 10 with version 3.6.7 of the Steinberg SDK. Tried to build with VS 2015 and that failed too. ---
**Author:** ![fr810](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/fr810/32/841_2.png) [@fr810](https://forum.juce.com/u/fr810)\ **Post date:** [October 7, 2017, 12:48pm UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/2 "2017-10-07T12:48:26Z")
That’s very odd! Are you using the latest JUCE version? The plug-in host with VST3 support is built automatically for Windows (with VS2017) with our build server every time we commit something, so it’s odd that we haven’t spotted this yet. ---
**Author:** ![wub](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/wub/32/2908_2.png) [@wub](https://forum.juce.com/u/wub)\ **Post date:** [October 7, 2017, 1:23pm UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/3 "2017-10-07T13:23:56Z")
Using JUCE v5.1.2 build 18 Sep 2017. I got a different build error message with an older version of Steinberg. When I got the latest Steinberg, that error went away, but the new error popped up. I’m simply navigating to the plugin host folder and double clicking on the jucer file and building. ---
**Author:** ![fr810](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/fr810/32/841_2.png) [@fr810](https://forum.juce.com/u/fr810)\ **Post date:** [October 9, 2017, 9:02am UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/4 "2017-10-09T09:02:50Z")
Sorry, I really don’t know what could be causing that error. ---
**Author:** ![jules](https://avatars.discourse-cdn.com/v4/letter/j/41988e/32.png) [@jules](https://forum.juce.com/u/jules)\ **Post date:** [October 9, 2017, 9:06am UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/5 "2017-10-09T09:06:57Z")
Our latest code definitely includes the flock.cpp file that contains those functions, so if you’re building with it, there’s not really any way it could be a missing symbol. I can only think that maybe you’re not building with the right paths or versions of juce/VSTSDK that you think you are. ---
**Author:** ![spcplugins1](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@spcplugins1](https://forum.juce.com/u/spcplugins1)\ **Post date:** [November 9, 2017, 9:39pm UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/6 "2017-11-09T21:39:59Z")
I’m getting a similar error when trying to build a project started in Juce 4 (or was it 3?) using the latest Juce 5, VS2013, and VSTSDK 3.6.8: Error C1083: Cannot open include file: “base/source/flock.cpp” Presumably because flock.cpp is actually in: “base/thread/source/flock.cpp”? ---
**Author:** ![jrlanglois](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/jrlanglois/32/21372_2.png) [@jrlanglois](https://forum.juce.com/u/jrlanglois)\ **Post date:** [November 9, 2017, 9:41pm UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/7 "2017-11-09T21:41:50Z")
Please see [No flock.cpp in VST SDK?](https://forum.juce.com/t/no-flock-cpp-in-vst-sdk/25069) ---
**Author:** ![spcplugins1](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@spcplugins1](https://forum.juce.com/u/spcplugins1)\ **Post date:** [November 10, 2017, 8:42am UTC](https://forum.juce.com/t/cannot-build-plugin-host/24539/8 "2017-11-10T08:42:26Z")
Cheers!