err
 

[UEqn.H:35: error: no match for ‘operator+’ in ‘Foam::operator*(const Foam::tmp<Foam::GeometricField<double, PatchField, GeoMesh> >&, const Foam::GeometricField<double, PatchField, GeoMesh>&) [with PatchField = Foam::fvsPatchField, GeoMesh = Foam::surfaceMesh](((const Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh>&)((const Foam::surfaceScalarField*)mesh.Foam::fvMesh::magSf ()))) + Foam::operator*(const Foam::GeometricField<Type, PatchField, GeoMesh>&, const Foam::GeometricField<double, PatchField, GeoMesh>&) [with Type = Foam::Vector<double>, PatchField = Foam::fvPatchField, GeoMesh = Foam::volMesh](((const Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&)((const][/CODE]

You need to re-check your solver file. UEqn is having a problem with the terms described in it, for example an unrecognized syntax.

May be you can copy paste your solver file here.