I have been doing more work on the upgrading to TWS 856 and found that I have no problem in upgrading from TWS 855 to TWS 856. The problems are in upgrading from TWS 853.8 to TWS 856 (all of my page layouts were lost and not listed under PAGE > SETTINGS > LAYOUTS and TWS 856 Trading page reverted to the DEFAULT LAYOUT PAGE). I found I was able to run the Previous TWS 855 download from IB's web site and install the Previous TWS 855 over my TWS 853.8 with no problems and then upgrade the resulting TWS 855 to TWS 856 with no problems. IB Tech needs to fix this problem with upgrading of older versions of TWS to TWS 856. I had this exact same problem several months ago when upgrading an older version of TWS, pointed the problem out to IB Tech and they fixed the problem for everyone. Well, it looks like the IB software writers need to correct the problem once more.
This seems to be the price to pay for useless complexity. Taking a look at Inreractive Broker's own Forum pages, it amazes me how few posts still deal with relevant API trading topics - except of course for complaints about those crazy and perfectly useless popups making people look for adequate solutions everywhere. The huge mass of posts is now from people whining and complaining about backfill problems and charting problems - not trading. Luckily, IB learned their lesson. I must say that the last months they seem to give absolute priority to getting their quote-streams out, a few very minor incidents excepted. This is very positive. If they would manage to clean up that other mess, they will go to the stars. I am sticking to 855 right now.