PC with SP4 64bit: load CAN dbc File does not work

We have to load a CAN .dbc File in SP4 64bit on a measurement PC with 1xSirius + 1x Dewe43. We see the DS sheets CAN1-3, but after .dbc "import" nothing happens: no error message appears and the CAN message table is still blank after import. Any idea what the reason is?

On my office PC with SP4 32bit in simulation mode the .dbc import works (same .dbc).

2nd question: how can I delete a CAN-ID in the CAN table after dbc import in Dewesoft?

For importing the *.dbc file Dewesoft uses Visual C++ Redistributable for Visual Studio 2015. 

If this is not installed, it can be downloaded from this link: https://www.microsoft.com/en-us/download/details.aspx?id=48145

Use the same version as Dewesoft:

Dewesoft 64-bit -> vc_redist.x64.exe

Dewesoft 32-bit -> vc_redist.x86.exe

The Visual C++ Redistributable for Visual Studio 2015 is also installed with Dewesoft X3 SP5 installer and newer.