VMachine works windows FREEZE

Hello there. I am using VirtualBox Version 5.1.26 (the latest version, which I could download from the website) and I tried to run a VMachine with Windows 10 (guest OS) on MacOS (host OS ). There was no problem until yesterday. Windows 10 was installed and working perfectly on the VBox.
However today when I tried to use Virtualbox again and tried to start the virtual machine. It too like half a minute to just open the VirtualBox initial Window of the VM where it just says the virtual machine logo. There was no other program running on my Mac at that time by the way. After that the Virtualmachine booted normally however I heard the welcome sound of Windows without the screen actually showing the windows desktop. So I started to understand that there was I big problem with the whole windows manager of the VirtualBox or the Mac I do not know.
I then tried to click on Window and start using them. When I click the colour wheel of MacOS appeared I could do nothing and on the task manager the VM process was declared as not responding. After 30 sec I was in Windows with the windows clicker. Then I tried to go to Mac . Again the colour wheel waited about 1 min and then I could use MacOS. So from my little understanding I think that there must be a serious problem with the windows manager.
Also forgot to mention. While I was waiting after I hit the start button for the Windows machine to start the VBox manager open himself a subwindow with a progress bar and there something like creating Qt Process 1/2 or something like that. It disappered in like 3 sec but I think it underlines even more that there must be some Window Manager Problem.
Anyway I tried everything humanly possible uninstalled installed all again for the start I even installed Qt 5.6 but still the windows will freeze for 10 - 30s. Even when I will close the whole program it will take like 30s after I have given the command to quit. I have never come across to something like that so I do not know what other information, log files or .... to give you.
Please give some suggestions. If you need any other information from my side please let me know. I will try to give answer as some as possible. Thank you in advance for you help and you time and wish we can resolve it together.
Forgot to mention that I also tried it with a Linux image. Again the same window manager problems thank you
However today when I tried to use Virtualbox again and tried to start the virtual machine. It too like half a minute to just open the VirtualBox initial Window of the VM where it just says the virtual machine logo. There was no other program running on my Mac at that time by the way. After that the Virtualmachine booted normally however I heard the welcome sound of Windows without the screen actually showing the windows desktop. So I started to understand that there was I big problem with the whole windows manager of the VirtualBox or the Mac I do not know.
I then tried to click on Window and start using them. When I click the colour wheel of MacOS appeared I could do nothing and on the task manager the VM process was declared as not responding. After 30 sec I was in Windows with the windows clicker. Then I tried to go to Mac . Again the colour wheel waited about 1 min and then I could use MacOS. So from my little understanding I think that there must be a serious problem with the windows manager.
Also forgot to mention. While I was waiting after I hit the start button for the Windows machine to start the VBox manager open himself a subwindow with a progress bar and there something like creating Qt Process 1/2 or something like that. It disappered in like 3 sec but I think it underlines even more that there must be some Window Manager Problem.
Anyway I tried everything humanly possible uninstalled installed all again for the start I even installed Qt 5.6 but still the windows will freeze for 10 - 30s. Even when I will close the whole program it will take like 30s after I have given the command to quit. I have never come across to something like that so I do not know what other information, log files or .... to give you.
Please give some suggestions. If you need any other information from my side please let me know. I will try to give answer as some as possible. Thank you in advance for you help and you time and wish we can resolve it together.
Forgot to mention that I also tried it with a Linux image. Again the same window manager problems thank you
