[ROBBIE HALL]

Using a Lumia 1020. Installed preview for developers. Firmware 3051.50009.1424.0001 (is this Denim?)
Since that I've realized that sending a voice note via WhatsApp no longer works. I can see the mic, press and hold, see the recording timer but on release of the mic icon, the voice note doesn't send. (you hear the sound/chime like its been cancelled. It worked before. Anyone else with the issue? Any suggestions?

[gpobernardo]

Using a Lumia 1020. Installed preview for developers. Firmware 3051.50009.1424.0001 (is this Denim?)
Since that I've realized that sending a voice note via WhatsApp no longer works. I can see the mic, press and hold, see the recording timer but on release of the mic icon, the voice note doesn't send. (you hear the sound/chime like its been cancelled. It worked before. Anyone else with the issue? Any suggestions?

The Firmware revision number you posted is the same as the one available for Cyan. L1020s who received the official (not preview for developer) Denim update register Firmware version 3051.50009.1451.100X. However, with Preview for Developers installed you may already have most of the features the official Denim update will deliver. A known bug with the Extras+Info would even show you that you've got "Denim" as soon as you disable preview for developers.

As for the error, try either both restarting and performing a soft reset on your phone or either one and see if that resolves the issue. You may also need to reinstall the app if restarting or performing a soft reset does not work.

To perform a soft reset, press the power button and the volume down button together until your phone restarts.
To restart, just turn your phone off and then turn it on again.

[ROBBIE HALL]

Will a soft reset delete any user data? Tried reinstalling...no luck...
Is this FW available without PFD?

[Schnuffi]

Will a soft reset delete any user data? Tried reinstalling...no luck...
Is this FW available without PFD?

No it won't