Value cannot be null. Parameter name: connectionString appsettings.json in starter

Question

I am trying to write my connection string in my appsettings.json file and bring it into my startup file but I keep getting a Value cannot be null. Parameter name: connection

Answer 1

I got this because I had a connection string with a \ in it, which needed escaping to be a \\. So my localdb connection string was causing a load error like this:

"DefaultConnection": "Server=(localdb)\myinstance;Integrated Security=true;Initial Catlog=my-localdb;"

and was fixed by making it:

"DefaultConnection": "Server=(localdb)\\myinstance;Integrated Security=true;Initial Catlog=my-localdb;"