Don't upgrade from 5.2.6.7 to 5.4.0.49

Hi all,

I just found out a major firmware-bug in the latest firmware (5.4.0.49).
After updating my C26b-AU-6N with Mx-A-IOA-IC from version 5.2.6.7 directly to 5.4.0.49 the MX-bus and the IO’s where not available.
Even downgrading back to 5.4.0.45 did no good.
I had to go back to 5.2.6.7 and from there to 5.4.0.45 and finaly to 5.4.0.49.

Greatings Erwin