I will try it, or can i just use the old blk0001.dat and blkindex.dat from version 2.1.1.1? At every wallet update i backed up the appdata directory of microcoin and deleted the files except wallet.dat and microcoin.coinf in that directory to resync all blocks...
hmm, never deleted any .DAT files during 3 updates, all work fine
(facepalm)
Please for future reference each time an crypto coin has this kind of changes.
go into your coin data dir (usually user/appdata/roaming/coinx, and delete everything except wallet.dat
Then start the wallet and let it update to an clean and correct version of the blockchain.
This was also mentioned on the OP page that people had to do for the prev version.
The OP states this, but it isnt really necessary.
Not a single bit of the blockchain will be different, regardless if you delete before the update or not.
There are no "clean" or "dirty" versions of the blockchain.
edit: Always keep a backup (better more thane one) of your wallet.dat in a safe place, thats all you need, regardless of any updates.