Error 0

[Lwark28]

I keep getting error 0 when texting my friend. I can receive texts from her number, I can call her number, text all my other contacts. I can send her a text from my partners phone fine, just not from my phone. Both phones are on 02, hers is iPhone, mine is android (I only got this phone 2 weeks ago, transferred my number but used to be able to text her fine from old phone). 

Things I've tried: deleting and resaving her number, saving number with and without +44, tried both Samsung and google message apps, disabling them, checking the message centre number is correct, restarting phone, checking block lists. Near enough everything bar factory reset which I'm reluctant to do. 

Any advice? 

[MI5]

@Lwark28 

Likely to be that your friend has accidentally blocked you or still has your number saved as an iPhone number.

[Lwark28]

Would this still be the case if she can still text me and receive calls from me? 

[MI5]

Yes, same still applies @Lwark28 

There are separate call and text settings