One of your filters uses a custom header that contains an invalid character, such as ':', a non-printable character, a non-ascii character, or an eight-bit ascii character. Please edit the msgFilterRules.dat file, which contains your filters, to remove invalid characters from your custom headers.
Jedyn z filtrow wužiwarsku hłowu wužiwa, kotryž njepłaćiwe znamješko kaž ':' njećišćomne znamješko, nje-ascii-znamješko abo wosombitowe ascii-znamješko wobsahuje. Prošu wobdźěłajće dataju rules.dat, kotraž waše filtry wobsahuje, zo bychu so njepłaćiwe znamješka z wašich wužiwarskich hłowow wotstronili.