Why can't I get this Samsung Galaxy Core prime out of Odin and or IS?

[AC Question]

When I am in Odin mode, I press vol down, power, & home buttons. Then, it takes me to a screen that says,"Warning". A custom IS can cause critical problems in phone and installed applications.custom IS volume up, volume down key to cancel-restart phone. No matter what I choose, it takes me back to Odin?? Help me get out of this loop & reboot phone/factory reset.

 

[B. Diddy]

Welcome to Android Central! If you pull the battery, reinsert it and power on normally again, does it go back to Odin mode?

If you want to do a factory reset, are you following these exact steps? https://support.t-mobile.com/docs/DOC-27544

 

[smvim]

Since it sounds like you are stuck in a boot loop, with your Core Prime it does have a removable battery so try pulling the battery. Leave it out for a few minutes (this clears any residual power that remains in some internal components), and then put the battery back in and try to restart it again.
If it continues to boot back up into its Download Mode again, try booting up into into Recovery Mode (when starting, simultaneously holding down the Volume Up, the Home, and the Power buttons). Recovery Mode is a text only interface so you need to use the indicated keys to navigate through the different menus. Select the option to wipe the system cache partition. The system cache is separate and different from the general app caches and it will not affect your personal data so it's safe to do.
If after wiping the system cache still results in your Core Prime booting up into Download Mode, you could try booting up into Recovery Mode and this time doing a Factory Reset to see if that cures the problem but note that a Factory Reset will wipe all your files and other personal data. If you don't have your files backed up this should be a last resort measure.
You might want to try re-flashing the Samsung stock ROM. Flashing the ROM on an Android device is essentially the same as reinstalling the operating system on a PC. Also, if you follow directions (don't try to customize any steps or take any shortcuts) with your Core Prime you can flash a stock ROM without losing your personal data ( your data is stored in a separate /data partition while the operating system resides in its own distinct partitions). You don't need to root your device to flash a stock ROM, that only applies to flashing custom ROMs. Anyway, go to this site:
https://www.sammobile.com/firmwares/
and use the search box to find your stock ROM. Note that ROMs are very model specific so be absolutely sure you're getting one that matches your particular model of Core Prime and your carrier (different carriers rely on different cellular networks so the hardware chips in your phone will be different too). At the bottom the page for whichever ROM you've selected as instructions on the steps you need to follow to flash the ROM. Also keep in mind that sammobile intentionally restricts the bandwidth of its download servers so don't be surprised how long it takes to download a ROM even if you have a really fast connection on your end..