I'm suddenly unable to play multiplayer, it says I need an online pass to go onl

@Berndbrecht 

Please clear your temp files:

• Press the Windows key and "R" at the same time
• Into the new window, type or copy & paste:  "%temp%"   (Without the quotes.) > hit "ENTER"
• Now your Windows Explorer should have brought you to the "C:\Users\>your user name<\AppData\Local\Temp" folder. > Delete all files and folders in it.
  (If some files or folders can't be deleted, reboot and try again.)

Then clear your Origin cache.
All settings in Origin (only in Origin not in the games) are back to default settings after this.)

• Close Origin completely.
  (right click on the Origin symbol in the task bar > close)
• Press the Windows key and "R" at the same time.
• Type or copy and paste "%ProgramData%/Origin" (without quotes) into the new window > hit ENTER
• Delete all the files and folders in the Origin folder, except for the "LocalContent" folder.
  (The "LocalContent" folder must remain untouched.)
• Delete the "Mass Effect 3" folder from inside the "LocalContent" folder.
• Press the Windows key and "R" at the same time.
• Type or copy and paste "%AppData%" (without quotes) into the new window > hit ENTER
• Now your Windows explorer should have brought you to your "C:\Users\>your user name<\AppData\Roaming" folder.
• Delete the "Origin"  folder inside the "Roaming" folder.
• In the address bar of your Windows explorer click on "AppData".
• Open the "Local" folder.
• Delete the "Origin"  folder inside the  "Local" folder.
• Restart your PC. > test

If that don't helps it is probably a account problem.

• The link to EA's Support is here. If you are not from the US change the country in the top right corner.
• Choose "Contact us" (Top Bar) and then Choose "Origin" from the list. (Or search for it.)
• Choose PC > Choose "Manage my Account" > "Can't log in" > Select contact Option.
• You should get a chat option now. (Please note the business hours.)

You also could try EAs Support on Twitter or on Facebook.

Thank you for the quick answer, unfortunately that didn't work so it's probably an account thing like you said.

I have tried to contact EA Support, however since I'm from Europe (Belgium) the only support option that I get is using Answer HQ. I don't get any other option (I've sent an email but have had no reaction to it just yet).

Maybe I'll try Twitter or Facebook next to see if I am even able to get someone from EA.

All right so while waiting for an answer from EA Help, I figured I'd try to login on the N7 HQ website to see my multiplayer stats, and I was still able to see everything as if I was able to play multiplayer. (I was also able to play the galaxy at war minigame thingy.)

I also have tried to both repair and reinstall Mass Effect 3 (including all dlc's) and the origin client as well. When starting up the game it still says I don't have an online pass.

@Berndbrecht 

I am from Europe too and get a chat option without a problem.

Restarting the router, changing the region to English (if not already set this way), changing Browsers (to internet Explore), disabling add-ons especially anti-script and ad-block software or the windows firewall and the virus scanner for the contact attempt could help.

 Here is an EA contact guide.

 If all this fails and call becomes the only option, you can use a Voice-Over-IP service like Skype, Viber, or Google Voice for this call to reduce the cost. Just put your location in the Voice-Over-IP service to UK. (UK number  +44 203 0141818 (Available 9AM-9PM GMT, Monday through Saturday)

 More international Telephone numbers:

France:  +33 4 81 68 08 08
Germany +49 221 37 050 193

 
As said, you also could try EAs Support on Twitter or on Facebook.

Thank you!

I'll try to contact Support outside my country maybe they will actually respond!