Player can't find needed decoder for any FLV files.
Resolving for this problem:
Step by step instructions for resolving this problem:
1) Please, download on page SourcForge.net latest archive included DirectShow Filters - FLV Splitter, examples - FLVSplitter_20081115.zip.
2) Close The KMPLyer and unzip this archive in to The KMPlayer folder and overwrite existing the FLVSplitter.ax file.
Notes: don use any executable compressors for compress the FLVSplitter.ax file - this filter not works if compressed!
3) Run on command in to The KMPlayer folder regsvr32 FLVSplitter.ax
4) Restart The KMPlyer and play FLV Video just select this file on File -> Open File (Ctrl+O) dialog.