Bug #101327 to fix the bug.
Submitted: 27 Oct 2020 2:33 Modified: 27 Oct 2020 9:14
Reporter: dikshant chaudhary Email Updates:
Status: Can't repeat Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version: OS:Any (na)
Assigned to: CPU Architecture:Any (na)

[27 Oct 2020 2:33] dikshant chaudhary
Description:
Tried the same but not luck. mysql command prompt is working but not workbench 6.3, what to do else?

How to repeat:
nothing

Suggested fix:
static FontsUtils()
    {
        _fontsMapping["monospace"] = "Courier New";
        _fontsMapping["Helvetica"] = "Arial";

        foreach (var family in FontFamily.Families)
        {
            _existingFontFamilies.Add(family.Name, family);
        }
    }
With this code:

static FontsUtils()
    {
        _fontsMapping["monospace"] = "Courier New";
        _fontsMapping["Helvetica"] = "Arial";

        foreach (var family in FontFamily.Families)
        {
            if (!_existingFontFamilies.ContainsKey(family.Name))
            {
                _existingFontFamilies.Add(family.Name, family);
            }
        }
    }
[27 Oct 2020 9:14] MySQL Verification Team
Not enough information was provided for us to be able to handle this bug. Please re-read the instructions at http://bugs.mysql.com/how-to-report.php 

If you can provide more information, feel free to add it to this bug.

Thank you for your interest in MySQL.