Two keywords, func and function, were removed in Adaptive Server 12.5.4, making it possible to create identifiers using these names. If you did not use these as identifiers under 12.5.4, no action is needed. If you did, the parser generates a syntax error under 12.5.0.x since it interprets these words as keywords.
See “Additional steps required if you used 12.5.4 features before downgrading” for more information.