conformability error r(503)

I need help regarding the mlogtest for mlogit. There is an issue of "conformability error r(503)" for the mlogtest. The first 3 specs of my mlogit result results come out OK. But not for spec 4-6.

**Spec 1
mlogit SelfEmplStatus Foreignborn OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Male==1
mlogit SelfEmplStatus Foreignborn OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Female==1

**Spec 2
mlogit SelfEmplStatus OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other Buddhist Hindu Jewish Muslim Sikh AnyOtherReligion NoReligion Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Male==1
mlogit SelfEmplStatus OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other Buddhist Hindu Jewish Muslim Sikh AnyOtherReligion NoReligion Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Female==1

**Spec 3
mlogit SelfEmplStatus Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Male==1
mlogit SelfEmplStatus Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Female==1

***Test of Independent Variables
mlogtest, lr
mlogtest, wald
***Test of IIA
mlogtest, iia

I experienced a conformability error r(503) for spec 4 to spec 6. I'm not sure how to solve this issue. Is it just the mlogtest command contribute to this error? I would appreciate if someone could advice me on this matter because I already spend almost a month trying to find a solution

**Spec 4
mlogit SelfEmplStatus Foreignborn Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Male==1
mlogit SelfEmplStatus Foreignborn Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Female==1

**Spec 5
mlogit SelfEmplStatus Foreignborn Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Male==1

mlogit SelfEmplStatus Foreignborn Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012, base(1), if Female==1

**Spec 6
mlogit SelfEmplStatus Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other SINGLE DIVORCED WIDOWED Buddhist Hindu Jewish Muslim Sikh AnyOtherReligion NoReligion HigherEducation GceAlevel GcseOlevel OtherQualification NoQualification NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012 Arrivedbefore1980 Arrived1980TO1989 SE19701979 SE19801989 SE19901999 SE20002009, base(1), if Male==1
mlogit SelfEmplStatus Age16to25 Age26to35 Age36to45 Age46to55 OtherWhite Mixed Indian Pakistani Bangladeshi Chinese OtherAsian Black Other SINGLE DIVORCED WIDOWED Buddhist Hindu Jewish Muslim Sikh AnyOtherReligion NoReligion HigherEducation GceAlevel GcseOlevel OtherQualification NoQualification NorthEast NorthWest Yorkshire Midlands EastEngland London SouthEast SouthWest Wales Strathclyde Y2008 Y2009 Y2010 Y2011 Y2012 Arrivedbefore1980 Arrived1980TO1989 SE19701979 SE19801989 SE19901999 SE20002009, base(1), if Female==1

Regards
Shahbani