Hey there, @Joanndelph13. You can go to the application manager and uninstall the app and install it again. That may fix the issue.
We recommend hard resetting your device. Hard resetting your device restores your phone to its factory defaults. This reset erases all saved contacts, text and picture messages, or bookmarked Web pages. Any digital content such as wallpapers, ring tones, games and applications that were purchased before performing this reset will also be erased. Data/images stored in the Micro SD card will not be impacted. Please, try the following steps to hard reset your device:
1. With the device turned off, press and hold the Volume down key.
2. With the Volume down key held down, press and hold the Power key.Release the Power key when the ZTE logo appears.
3. Release the Volume Down key when the Android system recovery screen appears.
4. Use the Volume down key to scroll to wipe data/factory reset. With wipe data/factory reset highlighted, press the Power key.
5. Press the Volume down key to scroll to Yes -- delete all user data.With Yes -- delete all user data highlighted, press the Power key.
6. Once the wipe is complete, with reboot system now highlighted, press the Power key. The device will restart.
7. The device is now reset and ready for use.
I have been having the same problem with this phone. Completed the reset then the phone stated my SD card was bad. This is the third SD card I have used for this phone as it is the third time I have gone through with this process. Although I did like this phone I find it likes to not read SD cards at its will which can be a pain.