218: Unexpected character in module name

You linked a module with either [t-…]-> or [x-…]-> where the ellipsis represents the module name and optionally also a clue, a short description. The module name may not contain a dot . and at most one slash /, but it contains a dot and/or multiple slashes in your case.

Solution

Make sure that module name and an optional clue are separated by a colon like in the following example. While the module name must not contain a dot or multiple slashes, the clue can:

[t-poem:Penquist's "He/she/it stole my bike"]->bike.txt

Do not put dots in module names.
A single slash in a module name indicates the use of a sub-module:

[t-poem/sonett]->the-new-colossus.txt

While sub-sub-modules with two slashes are not supported, module developers can easily create another sub-module, if necessary:

[t-poem/spenserian-sonett]->amoretti-75.txt

If you did not mean to link a module at all, you can prepend the left square bracket with a backslash: \[