NWBC 5.0 and (from SAP) used MS-Tools MS.NET + MS.VisualStudio 2012, installation issues

we are facing some issues with NWBC 5.0 (some with PL-6 and other with PL-7)

and some unusual session-aborting

what can we (SAP customer) could make wrong with server installation or client-desktop installation?

of MS-Tools needed for SAP-NWBC ?

MS.NET 4.5.

included MS-VisualStudio-2012

a)

after installing NWBC-5.0 PL-7 we had:

NWBC.exe crashes with:

- tabItemStyle resource not found

- unable to cast object of type MS.internal.Named.Object to Type System.Windows.Style

before with NWBC-5.0 PL-6 we got:

object refrenence not set to an instance of an object.

after a google:

=> https://scn.sap.com/thread/3648327 und => https://scn.sap.com/thread/3648327

This is a generic Microsoft VB / .Net error message. It could be any or all of the following:

installation order conflict / unforseen installation error, due to missing .. user permissions,

missing MS pre-requisite, or missing/conflicting MS update. I would recommend you uninstall and try again.

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b)

NWBC.exe crashes with:

Problemsignatur:

Problemereignisname: CLR20r3

Problemsignatur 01: NWBC.exe

Problemsignatur 02: 50000.1503.18048.5840

Problemsignatur 03: 5508ee52

Problemsignatur 04: WindowsBase

Problemsignatur 05: 4.0.30319.34209

Problemsignatur 06: 5348b4e9

Problemsignatur 07: 1489

Problemsignatur 08: 40

Problemsignatur 09: RML5K4UDBMA5NI04CIYRWVDHKEWFDHCV

Betriebsystemversion: 6.1.7601.2.1.0.16.7

Gebietsschema-ID: 1031

Zusatzinformation 1: 0a9e

Zusatzinformation 2: 0a9e372d3b4ad19135b953a78882e789

Zusatzinformation 3: 0a9e

Zusatzinformation 4: 0a9e372d3b4ad19135b953a78882e789

i did a google-search: maybe this could match:

Visual Studio 2013 Professional crashes on startup

possible solution:

de-install MS.NET 4.5.2. and re-install MS.NET (as administrator)

=================

any idea ?