If you have Onebox development or testing VMs, you may find that the system stops working for no reason and you now get "Server 500" errors when you try and login to it.
There can be many causes for this, but one very subtle, but usually easy to fix cause, is that there is a discrepancy between the Onebox machine's server date and time and the "outside worlds" real date and time.
If you get Server 500 errors and it is not obvious as to why that is, then do a check the date and time of the Onebox machine versus your local systems date and time. To ensure they are within a few seconds of each other.
This can be done from the Administrator Command Prompt window (you need an Administrator command prompt window if you need to change the system date or time).
Do launch and Administrator command prompt do this in the Search area of your Windows start menu.
press The Windows key, to bring up the start menu. Then in the search window enter "command".
Look for the entry named "Command Prompt", then right click on it and select "Run as administrator" to lauch the Command prompt in Administrator mode.
The opened Command prompt window will show a title of "Administrator: Command Prompt" to remind you this has administrator privileges (so that you can change the date or time of the server).
Now, check the date is correct, enter "date" in the command prompt window and check the date shown is correct (note the "Enter the new date:" prompt shows the date format in brackets that the date is displayed in and also lets you know the date format you need to enter it in.
In the screenshot below, the date format is DD-MM-YY format so the current date shown is day then month then year.
I enter the correct date (11th of June 2025 is entered here as 11-06-25).
And pressed Enter.
If the date shown is correct, you can just press Enter to leave the date unchanged.
Then check the time using the "time" command in the prompt window.
This then shows the current time (in your display format for time).
If the time is incorrect (remembering that time doesn't update onscreen in this prompt, so the time shown is what is was when you ran the time command). Then you need to change it and should enter it in the format of HH:MM:SS.
If the time is correct, you can just press Enter to leave the time unchanged.
Check that the time shown is not too far behind the actual outside world time.
But also check it is not ahead of that correct time - and ensure you change it so it is no longer ahead of the real time if so.
If you find the date and time is incorrect and once, having changed the system date and time.
Refresh your Onebox client session - if it now works ok, then the incorrect date and time was the cause of the server 500 errors.