Hello, I don't know how to process with this error when linking a new Projeckt. Could anyone has a suggestion? Best regards -Emeric *** WARNING L23: UNRESOLVED EXTERNAL SYMBOLS *** ERROR L128: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: xSerialPortInitMinimal?T ADDRESS: 00081C78H *** ERROR L128: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: xSerialPutChar?T ADDRESS: 00081D06H *** ERROR L128: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: xSerialGetChar?T ADDRESS: 00081D78H *** ERROR L128: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: xSerialGetChar?T ADDRESS: 00081DD2H Program Size: data=6154 const=281 code=9248