For Windows 7, click the Start Button, then click Control panel, then Uninstall a program. Here are ways to remedy the error.

This should be enough, and no server IP or hostname is needed.Realms services are automatically set to a physical location nearest the Realm owner's IP. Trying to join my realms with mc 1.16 pre5 and then with 1.15.2 worked for me "Minecraft" is a trademark of Mojang Synergies AB, By continuing to use this website, you consent to the use of cookies in accordance with our, If using a wireless connection, ensure that you have a stable connection to your router, Try connecting using an Ethernet cable instead of using Wi-Fi, Try reverting to a previous backup using the backups list, If you have a firewall or antivirus, check the settings to be sure that it is not blocking or slowing your connection, Check your currently-running programs for anything that is using your internet bandwidth, then close those programs. If you're experiencing connection issues on Minecraft Realms for mobile, Xbox One, Nintendo Switch, VR, or Windows 10, go here. Open Task Manager by clicking Ctrl-Alt-Del at the same time. Here are ways to do it. If you're experiencing connection issues in Minecraft: Java Edition, go here. Here we list some definitions for the words contained in your error, in an attempt to help you understand your problem. If the error is related to a bad graphics driver, then you may do the following: If the error you are getting is related to the Internet Explorer, you may do the following: This repair tool can fix common computer problems such as blue screens, crashes and freezes, missing DLL files, as well as repair malware/virus damage and more by replacing damaged and missing system files. Whatever the case may be, the problem must be resolved immediately to avoid further problems. To find out more, contact your internet service provider.Invalid session ID  This error can easily be fixed by logging out of the game and back in to refresh your session ID. Click Uninstall on top of the list, and when it is done, reboot your computer. If I try downloading the backup or reverting to one it will give me a "could not restore the backup (500)" error. Though this symptom is largely due to virus infection, it can be attributed as a symptom for runtime error, as virus infection is one of the causes for runtime error. Make sure you update your virus program and run a thorough scan of the computer or, run Windows update so you can get the latest virus definition and fix. It can replace missing operating system files and DLLs, remove malware and fix the damage caused by it, as well as optimize your PC for maximum performance. If a repair method works for you, please click the upvote button to the left of the answer, this will let other users know which repair method is currently working the best.

This also applies to the same error being displayed when starting the game. (World is busy). I cant switch worlds, start a mini game, backup the current world, reset the current world. Click the Program which is causing the runtime error, then you may choose to uninstall or click Advanced options to reset the application.