Avoid error with MATLAB classes that we can't handle

src/MAT_HDF5.jl

@@ -169,6 +169,9 @@ function m_read(dset::HDF5Dataset)
             end
         end
         return out
+    elseif !haskey(str2type_matlab,mattype)
+        @warn "MATLAB $mattype values are currently not supported"
+        return missing
     end
 
     # Regular arrays of values
@@ -272,7 +275,7 @@ Return a list of variables in an opened Matlab file.
 
 See `matopen`.
 """
-names(f::MatlabHDF5File) = filter!(x->x != "#refs#", names(f.plain))
+names(f::MatlabHDF5File) = filter!(x -> x!="#refs#" && x!="#subsystem#", names(f.plain))
 
 """
     exists(matfile_handle, varname) -> Bool

test/read.jl

@@ -212,3 +212,14 @@ let objtestfile = "figure.fig"
     @test vars["hgS_070000"]["handle"] == 1.0
     @test vars["hgS_070000"]["type"] == "figure"
 end
+
+# test reading file containing Matlab table and datetime objects
+# since we don't support these objects, just make sure that there are no errors
+# reading the file and that the variables are there and replaced with `missing`
+let objtestfile = "struct_table_datetime.mat"
+    vars = matread(joinpath(dirname(@__FILE__), "v7.3", objtestfile))["s"]
+    @test "testTable" in keys(vars)
+    @test ismissing(vars["testTable"])
+    @test "testDatetime" in keys(vars)
+    @test ismissing(vars["testDatetime"])
+end