Hello. I upgraded a 6.2.9 site to most recent DNN 7.

I cannot access host settings. Has anyone seen this error? thanks

Error: Host Settings is currently unavailable. DotNetNuke.Services.Exceptions.ModuleLoadException: Invalid length for a Base-64 char array or string. ---> System.FormatException: Invalid length for a Base-64 char array or string. at System.Convert.FromBase64_Decode(Char* startInputPtr, Int32 inputLength, Byte* startDestPtr, Int32 destLength) at System.Convert.FromBase64CharPtr(Char* inputPtr, Int32 inputLength) at System.Convert.FromBase64String(String s) at DotNetNuke.Security.FIPSCompliant.DecryptAES(String encryptedText, String passPhrase, String salt, Int32 iterations) at DotNetNuke.Entities.Controllers.HostController.GetEncryptedString(String key, String passPhrase) at DotNetNuke.Entities.Host.Host.get_SMTPPassword() at DotNetNuke.Modules.Admin.Host.HostSettings.BindSmtpServer() at DotNetNuke.Modules.Admin.Host.HostSettings.BindData() at DotNetNuke.Modules.Admin.Host.HostSettings.OnLoad(EventArgs e) --- End of inner exception stack trace ---