Make sure your real debrid is up-to-date.
Re authorize your account
Delete your devices in real debrid and re add them
Make sure they are added in real debrid.
These steps are a must and will solve the issue 9 out of 10 times. Also check real debrids Twitter for status updates.
Please go threw the guides.
I would also use something els with realdebrid.
Take a look here for the best recommend aps with real debrid setup.