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You may find the the text editor becomes unresponsive and appears to lock up after you have backspaced , to attempted to edit previously entered text on in the mobile application.
The solution is to close then open the keyboard. Here’s how you do that.
Tap outside the field, into a blank space on the Announcement page.
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Your smartphone will close the keyboard
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because there’s nowhere to enter data.
Now tap the Announcement edit field again to open you want to edit, which opens the keyboard and so you can make your changes.