The fault only occurs using popups, but the error does not occur with respect to other functions of the dcx.dll
is a problem which affects content in dcx_tool.mrc aliases provided in support...type xpopup alias or not this I do not know...
in any case the alias you 've suggested returns me this error

;==============================================================;
alias load_dcx {
if ($dll(dlls\dcx.dll)) return
dll dlls\dcx.dll LoadDCX
}
-
* /dll: no such routine 'LoadDCX' (line 31, menu.vxd)
-

for eventual verification of placed the problem of link plugin

Thanks argv0

DCX xPopups

A Creative & Interactive mIRC Scripting