This error happens whenever the FIDL parser encounters a grammatically invalid token. This can happen many ways--for example a missing = for an enum member, an extra token such as library = what.is.that.equals.doing.there, and so on.
{% include “docs/reference/fidl/language/error-catalog/label/_bad.md” %}
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/bad/fi-0008.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
Generally, the fix to this problem will be adding a missing token or removing an extra one.
{% include “docs/reference/fidl/language/error-catalog/label/_good.md” %}
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0008.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
To avoid this error, do a once over on your *.fidl files to make sure they're grammatically correct.
