Suddenly bluetooth is not pairing

[Louise6000]

My Experia X (F5121) have been paired with both a couple of computers and a speaker (Tangent Voxel) for a long time. Suddenly it loses the pairing, and when trying to pair again the units apear om the list with a long number instead of the previous names (such as e.g. Voxel). When trying to pair/connect the answer is every time and no matter which unit I am trying to g'et the phone to pair with this: "...could not pair due to wrong pincode or key (translated from danish)".

I paired okay again with our VW car.

When letting it test the answer is, That the bluetooth work allright.

What to do???

[BrolasBrolas]

Would you mind deleting all the paired devices from your phone, and try to reconnect them? Maybe this will fix your problem. 

[Louise6000]

There is no paired now except the one to the VW. Why do you think it will help to remove that?

[Strampke]

Reset is a good option to improve performance.

[Louise6000]

Well, yes, your right, but that is not resetting as fare as I know.

All paired deviced went suddenly to not being paired. Later I successed in the pairing with the VW car - or the car had succes with my phone. When trying to pair anyother device the message is that pairing did not work due to either wrong pincode or accesskey.

So the question is "What is wrong?" or "What am I missing to do?"

[Strampke]

When you do reset network settings there will be no more wrong pincode or accesskey message because it is erased.

Cleaning up often resloves problems of which the cause is hard to retrieve.

The time spent on retrieving can be spent on better things than fighting software problems.

[Louise6000]

Okay, but I don´t know how to come around resetting network settings. Is it on the mobile phone? Can you walk me through it?