Oracle.ManagedDataAccess.EntityFramework - ORA-01918: user 'dbo' does not exist

I had the same problem and it was resolved by Thiago Lunardi's response. Thank you. I didn't have enough reputation to vote up your response. To mention here, I succeeded after setting my schema name in UPPERCASE.

Put this in your Context file under your new dbContext class, like this:

public partial class MyAppContext : DbContext
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.HasDefaultSchema("UPPERCASE_SCHEMA_NAME");
...

I solve this just setting the default schema at modelBuilder

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.HasDefaultSchema("MyOracleSchema");

    // ...
}

Setting default schema didn't work for me. I found the solution by customizing migrations history table to set a different schema.

You can find a solution here: LINK.