Where To Copy external dlls for SSRS SQL 2017

dear experts please guide

where to copy extrenal dll after installing sql 2017 and run report from vs2017 IDE ?

now i am unable to preview reports from vs2017 IDE after opening report projects 

each time either visual studio or sql version changes how to know the path where external dll used in .rdl are to be copied ?

so far vs2017 and sql 2016 the barcode library copied to following path reports run smoothly 

for vs2017
copy barcode.dll everywhere
as under
C:\Program Files\Microsoft SQL Server\MSRS13.MSSQLSERVER\Reporting Services\ReportServer\bin\barcode.dll

-- Since 7-7-2017 update to extensions path is changed
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\SSRS
-- Since 7-7-2017 update to extensions

C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE
C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE
C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE
C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE

Copy the barcode.dll to for for .rdlc reports inclusion in project to build failed error, it need to be kept in the folder where msbuild runs from and that can be seen by opening output window while build is run ( CTRL+W,O)
For vs2013/2012 (MSBuild) :
C:\Program Files (x86)\MSBuild\12.0\Bin


VS2017 community eddition (Msbuild)
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\PrivateAssemblies
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\SSDTRS

Last But not least:
copy the external .dll and .pdb to the bin\debug and bin\release directory of your application and include them in the project as content and copy newer files in the properties
for eg:
E:\17vs\Kings ERP\bin\Debug\barcode.dll