@maydin95 You are hero!

For everyone who is struggling with ths widevine DRM nightmare, and still have problems with "Enable secure playback in your browser" (or other) on Spotify Web Player using Opera here is what I did step by step (for newbie like me that are new to linux) to fix it:

I am using Opera 64.0.3417.92 and Deepin Linux 15.11.

1. Close all web-browsers.

2. Download this file https://gist.github.com/ruario/3c873d43eb20553d5014bd4d29fe37f1 then execute it in terminal

sudo sh latest-widevine.sh

This will download newest version of widevine (for today this is 4.10.1440.19) to /opt/google/chrome folder.

3. Using command

cd /usr/lib/x86_64-linux-gnu/opera/resources/

or file manager go to this folder and edit file widevine_config.json

I edited it so it looks this way:

(I don't know if it is super correct, but whatever)

4. Go to folder /usr/lib/x86_64-linux-gnu/opera and remove not working proprietary codecs file using command

sudo rm -f libffmpeg.so

5. Download this: https://github.com/iteufel/nwjs-ffmpeg-prebuilt/releases/
   (For today I used 0.41.3-linux-x64.zip)
   Extract file

libffmpeg.so

and copy it to the folder where you removed not working version with command:

sudo cp ~/Downloads/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera/

6. Run Opera browser. Visit https://bitmovin.com/demos/drm . If everything went OK then you will see
   

That mean that Spotify and Netflix should run on Opera browser without any issues.

Proof (that everything is working with Opera as well on Google Chrome)

@l33t4opera I confirm that widevine is fixed in Opera 67.0.3575.115 (working on Ubuntu 18.04 LTS) but in version downloaded from website as deb package (not through snap - opera installed with snap do not play spotify web)

@parmasampa Update: Opera 67.0.3575.115 on Ubuntu 18.04 LTS downloaded directly from Opera website plays spotify web out of the box!

Hey, check out this post and whole thread:
https://forums.opera.com/topic/28663/widevine-and-opera/56?_=1586288130120

I hope this help.

@paulkastel
I performed some updates of software and of operating system and Opera lost DRM support - again.

(This is joke from creators of Opera, that after all this time it works on macOS and Windows and Linux version of their product is not supported as well).

But - good news is that I performed same steps from my instruction but in step 5 I used newer version of codecs: 0.42.4-linux-x64.zip, and Opera ver. 65.0.3467.48 plays Spotify Web again.

@maydin95 You are hero!

For everyone who is struggling with ths widevine DRM nightmare, and still have problems with "Enable secure playback in your browser" (or other) on Spotify Web Player using Opera here is what I did step by step (for newbie like me that are new to linux) to fix it:

I am using Opera 64.0.3417.92 and Deepin Linux 15.11.

1. Close all web-browsers.

2. Download this file https://gist.github.com/ruario/3c873d43eb20553d5014bd4d29fe37f1 then execute it in terminal

sudo sh latest-widevine.sh

This will download newest version of widevine (for today this is 4.10.1440.19) to /opt/google/chrome folder.

3. Using command

cd /usr/lib/x86_64-linux-gnu/opera/resources/

or file manager go to this folder and edit file widevine_config.json

I edited it so it looks this way:

(I don't know if it is super correct, but whatever)

4. Go to folder /usr/lib/x86_64-linux-gnu/opera and remove not working proprietary codecs file using command

sudo rm -f libffmpeg.so

5. Download this: https://github.com/iteufel/nwjs-ffmpeg-prebuilt/releases/
   (For today I used 0.41.3-linux-x64.zip)
   Extract file

libffmpeg.so

and copy it to the folder where you removed not working version with command:

sudo cp ~/Downloads/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera/

6. Run Opera browser. Visit https://bitmovin.com/demos/drm . If everything went OK then you will see
   

That mean that Spotify and Netflix should run on Opera browser without any issues.

Proof (that everything is working with Opera as well on Google Chrome)