-try disabling all addons
-if that doesnt work, reinstall blockland
-update drivers
-if it still doesnt work, that could mean that you have big problems with your operating system. runtime errors often mean corrupted files or viruses. This will check for corrupted windows system files:
-go to start>all programs>accesories>system tools
-right click on command prompt and select run as administrator
-once in command prompt, type "sfc -SCANNOW" without parentheses