Can someone explain what it means ?

The message  was sent to everyone  it means nothing. It's just a test message as the message itself explains.  I imagine they testing as warning for adverse   weather conditions and outbreaks.

It's just an experimental mass broadcast msging system which MOI is implementing/testing, this is to inform incase of natural disasters etc.

Already been answered above but I sometimes wonder why people don't read messages properly.  The text message literally said "experimental test message" and in three languages!!!!.........................so why would you have to go somewhere or do something?.   I got it, looked at it and deleted it.   This is similar to text messages sent by Civil defence in practically every GCC country.

@XTang

Was thinking the same and then was forced to think on it with more empathy and this is what I concluded, there is  no rational or logical  answer to it.

People aren't rational  or logical when emotional. I imagine seeing a message from moi scared and intimated the op and even after reading it he couldn't shake the unease and  Seeked reassurance.

Yes it makes no sense as  it was explained in 3 different  languages as you said but I see people like op posting the same in reddit as well.

True...............I guess we can't expect a perfect world.

Now the news all over media platform are circulating to be safe and prepared for radiation incidents but yet no announcement officially from the government entities. I do not know what to make out of it. Little scared at the situation as literally now all my fam are out of Bahrain and I have troublesome mind deciding whether to stay or leave Bahrain. Is there any kind of situation going on that we are unaware of?  Just out of curiosity. So many things going on mind right now cause of the the chaos going on.

I pray for everyone to have a peace of mind and good health.

Here is what I think.  You need to rationalise based on logic  than fear. Fear is not logical.

Now as for why the bah govt has recently  been sending  such test messages I feel it simply  because they never had one in place before. 

The earlier emergency  alert messages are part of daily life in many parts of the world with severe climate warnings and natural disasters.   And yes also man made disasters like war especially things that are happening  now.

While no one can predict  how things can escalate  I don't think the current  situation affects our region and forsee any imminent threats to the gulf countries.

Also as an expat who was born and brought up in bahrain for Nearly 30 years and have had all my family relocate outside of bahrain I understand  your unease at being caught  in a war in a country with no family around.

As above by @leh95.  I think that the government should have realized how people love to speculate in this part of the world and maybe started with precautions of different types e.g. sandstorm etc. and then built it up to the radiation thing.  That way, it would be easier for people to realize that they are creating a repository of information to refer to in case of any disaster - pretty standard for most countries.

And yes, the emergency alert is normal.  I get like dozens a month from Saudi civil defence - it's just new for Bahrain.