Digitakt 1.30 : Bug reports

Can anyone give me info?
Like i mentioned in this tread OS 1.30 gave a lot of issues. I opened a support ticket yesterday to ask for OS 1.21A , but no reply yet. I found a link in a tread with the previous OS Old projects sounding different after 1.30 update and how to solve it - #12 by maerteijn
I downgraded the OS , and had no sound, reloaded project and it’s ok.
But now when i boot the digitakt it shows a E in the left corner in the boot screen.
I don’t recall seeing this ever, my intuition says E of error? What does this mean? The Digitakt functions normal.