Warning:
Instead of passing separate callback arguments, use an observer argument. Signatures taking separate callback arguments will be removed in v8
The solution is that instead of using the following signature:
.subscribe(
(data) => {
// success
},
(err) => {
// error
}
);
you need to use the following now:
.subscribe({
next: (data) => {
// success
},
error:(err) => {
// error
}
});