Here are multiple solutions to this problem!
Let's start with simple ones:
1- Driver Update
Make sure all of your drivers are up-to-date. (Graphics card etc.)
2- Game Update and Repair
Go to Origin, then right click Apex Legends. Select update game, then repair.
3- Windows Compatibility
Go to "C:\Program Files (x86)\Origin Games\Apex" (or wherever is your game located.)
Right-click r5apex - Properties - Compatibility - Click Run this program in compatibility mode for, then select Windows 7. Press "Apply", then "OK"
4- Easy Anti-Cheat Update
Go to "C:\Program Files (x86)\Origin Games\Apex\EasyAntiCheat" Run EasyAntiCheat_Setup. Press "Repair" then "Finish"
5- Disable Origin In-Game
Go to Origin Client, click "Origin" at the left corner - Application Settings - More - Origin In-Game - then turn off the indicator.
Now, it's time for more advanced fixes.
1- Clean Boot Your PC (AT YOUR OWN RISK)
Here is a tutorial about it:
https://support.microsoft.com/en-ae/help/929135/how-to-perform-a-clean-boot-in-windows
2- Update Your Windows (IMPORTANT, FOR WINDOWS 8.1 USERS, AT YOUR OWN RISK)
Go to Windows Control Panel - Write "Update" to the search slot - Click "Windows Update" - Change Settings - Never Check for update - Click "OK"
Download this: https://www.microsoft.com/en-us/download/details.aspx?id=53246
and this: https://www.microsoft.com/en-us/download/details.aspx?id=53217
3-Download Windows Troubleshooter
Here is the link:
https://support.microsoft.com/en-ae/help/4027322/windows-update-troubleshooter
It's very easy to use.
Sorry for my English, I hope this article helps you!