Issues with quantization, dense turned on

I was trying to quantize model which is having dense layers in the main script the dense layers are turned off, But if I uncomment the

´@register_annotate_function(“nn.dense”)´

which gives rise to tvm._ffi.base.TVMError: Traceback (most recent call last): [bt] (8) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::MixedModeMutator::VisitExpr(tvm::RelayExpr const&)+0x5c3) [0x7f75968f7dc3]

[bt] (7) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::MixedModeMutator::VisitLeaf(tvm::RelayExpr const&)+0x5a) [0x7f75968f46fa]

[bt] (6) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::MixedModeMutator::DispatchVisitExpr(tvm::RelayExpr const&)+0x1d) [0x7f75968f825d]

[bt] (5) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::ExprMutator::VisitExpr(tvm::RelayExpr const&)+0x8e) [0x7f75968f81ee]

[bt] (4) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::ExprFunctor<tvm::RelayExpr (tvm::RelayExpr const&)>::VisitExpr(tvm::RelayExpr const&)+0x91) [0x7f75968fcdf1]

[bt] (3) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::ExprFunctor<tvm::RelayExpr (tvm::RelayExpr const&)>::InitVTable()::{lambda(tvm::runtime::ObjectRef const&, tvm::relay::ExprFunctor<tvm::RelayExpr (tvm::RelayExpr const&)>)#6}::_FUN(tvm::runtime::ObjectRef const&, tvm::relay::ExprFunctor<tvm::RelayExpr (tvm::RelayExpr const&)>)+0x27) [0x7f75968f9d67]

[bt] (2) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::MixedModeMutator::VisitExpr_(tvm::relay::CallNode const*)+0x43) [0x7f75967b1d83]

[bt] (1) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(tvm::relay::ForwardRewriter::Rewrite_(tvm::relay::CallNode const*, tvm::RelayExpr const&)+0x779) [0x7f75967b5229]

[bt] (0) /home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/libtvm.so(+0xcb1deb) [0x7f75969c5deb] File “tvm/_ffi/_cython/./packed_func.pxi”, line 55, in tvm._ffi._cy3.core.tvm_callback

File “/home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/relay/quantize/_annotate.py”, line 108, in frewrite_with_guard return func(ref_call, new_args, ctx)

File “/home/.local/lib/python3.6/site-packages/tvm-0.7.dev1-py3.6-linux-x86_64.egg/tvm/relay/quantize/_annotate.py”, line 222, in multiply_rewrite raise ValueError TVMError: ValueError

any idea what could be missing