If you have alerts appear on screen but stay on screen indefinitely it is usually because of your security software attempting to deny CLR Browser on OBS or due to a missing alert animation.
You should first check in your alert box settings to ensure that you have both in and out animations. If you have selected "none" you must ensure that your animation is included inside of your custom code.
How to allow alerts with Kaspersky (could also apply to other anti virus softwares):
- Open settings in Kaspersky and find "Threats and Exclusions "
2. Next add the following file locations to Exclusions
C:\Program Files (x86)\OBS\OBS.exe
C:\Program Files (x86)\OBS\plugins\CLRHostPlugin\CLRBrowserSourcePlugin\CLRBrowserSourceClient.exe
C:\Program Files (x86)\OBS\plugins\GraphicsCapture\injectHelper.exe and injectHelper64.exe
C:\Program Files (x86)\OBS\QSVHelper.exe
3. You will need to save the settings added and restart your PC. After the restart it should be working normally again.