I have tried to upgrade my DNN YAF version(1.9.6.1) to version 2.1 according with this manual:
http://dnnyafnet.codeplex.com/wikipage?title=Installation%2fUpgrading&referringTitle=Documentation 
but after step 5b i have got an empty forum without my posts and messages.
Has someone faced with the same problem?

I have tried to upgrade my DNN YAF version(1.9.6.1) to version 2.1 according with this manual:
http://dnnyafnet.codeplex.com/wikipage?title=Installation%2fUpgrading&referringTitle=Documentation 
but after step 5b i have got an empty forum without my posts and messages.
Has someone faced with the same problem?

That happens sometimes a new board is created, you need to log in as host an go the the yaf module settings page in dnn, access able from the Module Action Menu (in dnn edit page mode), there you can select the correct board. There should be at least 2 entries.

I made all like you said, but found only one board in module configuration.
Should i see this window in the end of upgrade?
https://skydrive.live.com/redir?resid=AA34884A372A708D !146&authkey=!AAX6xaLAgOc9M-M&v=3&ithint=photo%2c.png

I made all like you said, but found only one board in module configuration.
Should i see this window in the end of upgrade?
https://skydrive.live.com/redir?resid=AA34884A372A708D !146&authkey=!AAX6xaLAgOc9M-M&v=3&ithint=photo%2c.png

No that means something went wrong, did you changed the changed the Database ObjectQualifier (YAF.DatabaseObjectQualifier in the appsettings) in the web.config that dnn uses? As i wrote in the documentation only when you use a custom value you need to change it in the web.config.