Multiple apps -> black screen while entering text

[Bert McGaughey]

Hi folks,

I have a weird issue with my phone. Details as follows.

Handset: Lumia 550
OS: 10.0.10586.164

When I go to enter text in certain apps, the screen goes completely black and you can't see where or what you are entering.

If you tap the back soft key, you return to your previous screen and carry on as normal. With whatever text you entered, wherever you entered it saved.

This happens with:

Evernote (Version 4.6.8.1166)
London Bus Checker (Version 1.1.3)
Tube Map Pro

Is there a global setting somewhere that is affecting this?

 

[Bert McGaughey]

Could a handset firmware update solve this?

 

[rdifiori]

Did you change your font size under settings? If so, try changing it back to the default.

 

[Bert McGaughey]

Ahhhh legend! What a random bug!

 

[Maurizio Troso]

Ahhhh legend! What a random bug!

Mine started some days after Redstone upgrade, then it come back to normal by itself (only few days ago there was the app update).
Mistery,
Only WhatsApp do that!