Making a local variable null in code locals then returning back to the code that had that code local will cause crash.

[Grossley]

https://user-images.githubusercontent.com/42724744/111921674-08d49400-8a53-11eb-8ea8-0662282a3848.mp4

[Jacky720]

The exception is thrown from Decompiler.cs#L1357. An appropriate fix might be to default new code locals to an empty string rather than permitting a null value.