Hello Alexei, here is another hairy one. 1. Problem: MSVC does not tag "extern cl_private_thing cl_I_constructor_from_UL (uint32 wert);" in cln/number.h with the cln namespace because it is declared inside the body of an inlined function (symbol created is

...

?cl_I_constructor_from_UL@@YAPAUcl_anything@cln@@K@Z<<)

But cl_I_constructor_from_UL is defined inside cln namespace in cl_I_from_UL.cc (symbol created is

...

?cl_I_constructor_from_UL@cln@@YAPAUcl_anything@1@K@Z<<)

So we get unresolved external symbols on every assignment and constructor operation. 2. Solution (rather, work-around): Create an auxiliary function cln::cl_private_thing cl_I_constructor_from_UL (uint32 wert); outside of namespace cln which references cln::cl_private_thing cln::cl_I_constructor_from_UL(wert); Note: The attached patch is exemplary only. As soon as the method to solve this issue is agreed on, similar patches will have to be made for other constructors Best regards, Jan