C# Interactive code completion gets broken after a broken code was input

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

---

Reproduction:

1. Open the C# Interactive Window
2. Type Write() (an incorrect invocation to Console.Write, the parameter for that method overloads is missing)
3. In the subsequent submissions, neither syntax highlight or code completion will work correctly
   • In the following screenshot, WriteLine("Hello world") was a correct statement, but it was marked error.
   • We type Wr and code completion no longer provides symbol candidates

This issue occurred after I upgraded to 17.4 preview 2.1.

---

Original Comments

Feedback Bot on 9/28/2022, 08:26 PM:

(private comment, text removed)

Feedback Bot on 9/29/2022, 01:33 PM:

(private comment, text removed)

WMJ on 11/1/2022, 11:37 PM:

(private comment, text removed)

---

Original Solutions

(no solutions)

[tmat]

@genlu