warning: #1441-D: nonstandard cast on lvalue

The instructions for posting source code are quite clearly stated:

www.danlhenry.com/.../keil_code.png

aren't they?

i haven't read it to be honest, I will rewrite it

sorry for the incovenience.

I will re-write the code:

startLinst(Timer_u *head){
    Timer_u *ptr;

    (Timer_u *)ptr->list1->pnext = *head;
}

where head is the pointer to the head of a linked list.

the ADT is:

typedef union TIMER_U{
    Timer4 *timer4;
    Timer3 *timer3;
    Timer2 *timer2;
    Timer1 *timer1;
}Timer_u;

typedef struct TIMER1{
    unsigned char TimerID;
    unsigned char cnt;
    unsigned char processo:6; unsigned char type:2;
    union Timer_u *pnext;
}Timer1;

Can anyone help me to avoid the warning message 1441?

There is a typo in your code:

union Timer_u *pnext;

The keyword union shouldn't be there. The compiler thinks that you are referring to a different type defined elsewhere, rather than to Timer_u.

Can anyone help me to avoid the warning message 1441?

Remove the cast!

Mike, thanks for the hint, but removing the union I got the error "undefined class storage", so I put the code
union TIMER_U before the definition of the structs timer1/2/3/4 and this will make the compiler happy.
this will we work in your opinion?

Jack, removing the cast I will get an error about an illegal assignment.

removing the union I got the error "undefined class storage", so I put the code union TIMER_U before the definition of the structs timer1/2/3/4 and this will make the compiler happy

Isn't it "undefined storage class" instead?
Besides, it seems to me it's not the right way to make the compiler happy. I think we're not seeing the whole picture: the code you posted is incomplete, it's not clear in what order things are declared and defined.

you are right some infos are missing:
the ADT is defined in a header file, in the inverse order: i mean the struct is defined before the union
this is the right order

typedef struct TIMER1{
    unsigned char TimerID;
    unsigned char cnt;
    unsigned char processo:6; unsigned char type:2;
    union Timer_u *pnext;
}Timer1;

typedef struct TIMER2{...} Timer2;
typedef struct TIMER3{...} Timer3;
typedef struct TIMER4{...} Timer4;

typedef union TIMER_U{
    Timer4 *timer4;
    Timer3 *timer3;
    Timer2 *timer2;
    Timer1 *timer1;
}Timer_u;

so I changed it in this way

union TIMER_U;
typedef struct TIMER1{
    unsigned char TimerID;
    unsigned char cnt;
    unsigned char processo:6; unsigned char type:2;
    union TIMER_U *pnext;
}Timer1;

typedef struct TIMER2{...} Timer2;
typedef struct TIMER3{...} Timer3;
typedef struct TIMER4{...}Timer4;

typedef union TIMER_U{
    Timer4 *timer4;
    Timer3 *timer3;
    Timer2 *timer2;
    Timer1 *timer1;
}Timer_u;

so I changed it in this way

Yes, this new version of the code looks right.
What about the code that throws the warning? Is the warning still there? Did you post the complete offending code?

I have removed the cast and the warning message is non more there :)
thanks for you help.