Install B1 Studio for Visual Studio 2015 to create add-on for SAP Business One.
1 - You need a login with administration permission.
1 - Close all your Visual Studio instances.
2 - Open windows registry typing the command below on run window:
3 - regedit
4 - Go to HKEY_CURRENT_USER\Software\Microsoft\VisualStudio on registry tree view, like image below:
5 - Rename folders (keys) started with 14.0 to 10.0 for B1 Setup understand the structure.
6 - Install B1 Studio for MS Visual Studio.
7 - Go to HKEY_CURRENT_USER\Software\Microsoft\VisualStudio on registry tree view again.
8 - Rename folders (keys) started with 10.0 to 14.0.
9 - Open Visual Studio 2015.
10 - Go to File > New Project > Templates > Visual C# and check if SAP Business One templates are installed.
*If you have an installation of visual studio 2010, you need to rename the registry folders started with 10.0 to OLD_10.0 and after you finish the step-by-step you must rename then to previous name.