Application ''quits unexpectedly'' instantly when opened

If you haven't rebooted into safe mode anytime recently you should try that to see if it helps. Let the Mac OS do drive directory repair, cache clearing and other misc housekeeping. Often just booting into safe mode and logging in, then immediately rebooting normally will resolve an issue.  You should do this with all your external peripherals disconnected but the keyboard and mouse. Press the Shift key until you see the Apple logo and progress bar when you restart you Mac.

Booting into Safe Mode… 

Use safe mode to isolate issues - Apple Support

Note– starting up in Safe mode could take 10 minutes or more. Be patient.

Does the problem persist while in Safe mode? 

Restart your Macintosh and re-evaluate the issue.

I'm going to link you to Apple's Font Book User Guide. There may be something useful there. I know there's a section on validating fonts that are installed on your Mac. If the issue stems from a corrupt font, maybe this can help.

Install and validate fonts in Font Book on Mac - Apple Font Book User Guide

hype19 wrote:

Hi,

I downloaded my stock broker's trading popular platform on my macbook air, but it crashes everytime I open it saying it quit unexpectedly. I tried uninstalling, re-installing, restarting my computer, etc. but nothing works. This platform works just fine on every other mac I have used. I opened it using terminal, and here's the error I got:

warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

[warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

[warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

[warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

[warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

[warn] kq_init: detected broken kqueue; not using.: Undefined error: 0

2020-03-21 21:22:04.232 QtWebEngineProcess[8915:274291] XType: failed to connect - Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service on pid 0 named com.apple.fonts was invalidated." UserInfo={NSDebugDescription=The connection to service on pid 0 named com.apple.fonts was invalidated.}

2020-03-21 21:22:04.232 QtWebEngineProcess[8915:274291] Font server protocol version mismatch (expected:5 got:0), falling back to local fonts

2020-03-21 21:22:04.232 QtWebEngineProcess[8915:274291] XType: unable to make a connection to the font daemon!

2020-03-21 21:22:04.232 QtWebEngineProcess[8915:274291] registering /System/Library/Fonts/*, /System/Library/Fonts/Base/*, and /System/Library/Fonts/Supplemental/* locally

Abort trap: 6

logout

Is seems like it's a font problem ? How can I solve this ? Please help! Thank you

Macbook information: macbook air, up to date (catalina, latest update)

Does not sound like the application is compatible. Check the developers website for more Support/help/FAQ