Help needed - Hammer editor doesn't compile map!

[SirFruity]

Hello, I got a problem about the Source Hammer editor.

I was about to compile my GMod map but suddenly I got this error message (on the picture: 'the system couldn't find the specific file')

I would really appreciate any help I can get.

Inside the 'Compile Process Window" is this message:
** Executing...
** Command: "D:\Programme\Steam\steamapps\common\GarrysMod\bin\vbsp.exe"
** Parameters: -game "D:\Programme\Steam\steamapps\common\GarrysMod\garrysmod" "d:\source mapping\gmod\ttt_urbanstreet"

Valve Software - vbsp.exe (Mar 10 2020)
12 threads
materialPath: D:\Programme\Steam\steamapps\common\GarrysMod\garrysmod\materials
Error opening d:\source mapping\gmod\ttt_urbanstreet.vmf: File d:\source mapping\gmod\ttt_urbanstreet.vmf, line 1: No such file or directory.

** Executing...
** Command: "D:\Programme\Steam\steamapps\common\GarrysMod\bin\vvis.exe"
** Parameters: -game "D:\Programme\Steam\steamapps\common\GarrysMod\garrysmod" "d:\source mapping\gmod\ttt_urbanstreet"

Valve Software - vvis.exe (Mar 10 2020)
12 threads
reading d:\source mapping\gmod\ttt_urbanstreet.bsp
Error opening d:\source mapping\gmod\ttt_urbanstreet.bsp

** Executing...
** Command: "D:\Programme\Steam\steamapps\common\GarrysMod\bin\vrad.exe"
** Parameters: -game "D:\Programme\Steam\steamapps\common\GarrysMod\garrysmod" "d:\source mapping\gmod\ttt_urbanstreet"

Valve Software - vrad.exe SSE (Mar 10 2020)

      Valve Radiosity Simulator     
12 threads
[Reading texlights from 'lights.rad']
[45 texlights parsed from 'lights.rad']

Loading d:\source mapping\gmod\ttt_urbanstreet.bsp
Error opening d:\source mapping\gmod\ttt_urbanstreet.bsp

** Executing...
** Command: Copy File
** Parameters: "d:\source mapping\gmod\ttt_urbanstreet.bsp" "D:\Programme\Steam\steamapps\common\GarrysMod\garrysmod\maps\ttt_urbanstreet.bsp"

The command failed. Windows reported the error:
  "Das System kann die angegebene Datei nicht finden."