It's happened a couple of times now, where I would be flying during the day, bright blue skys and sunny, pretty windy. And the OA warning message pops up, but there is no obstacle in my way. My drone wouldn't allow me to move forward. I had to land it in the field and turn it off.  

The most common reason is that the drone is flying toward a bright, low sun which it sees as an obstacle.
In that situation, it's a simple matter to switch the OA off (do you really need it anyway?) or turn the drone to fly a different course so it's not straight into the sun.

Labroides Posted at 6-19 16:45
The most common reason is that the drone is flying toward a bright, low sun which it sees as an obstacle.
In that situation, it's a simple matter to switch the OA off (do you really need it anyway?) or turn the drone to fly a different course so it's not straight into the sun.

Thanks! ill turn off the OA. I have flew it, in a different direction, still nothing. but what did help was flying backwards lol.  

At least you know the Obstacle Avoidance is working - if nowt else,  that's gotta be reassuring ???