Litecoin wallet failed to read block
This problem can be fixed easily by re-indexing all the blocks.
1. Open the windows command prompt. (start -> run -> CMD)
2. browse to the folder of you litecoin installation. ( cd “C:\Program Files (x86)\Litecoin\)
3. Stat the litecoin application with the extra value -reindex. (litecoin-qt.exe -reindex)
If everything went well your wallet will open again.