Being asked to "improve" a piece of internal software with not a single hint of what actually needed doing. After two meetings where nothing more concrete than

Being asked to "improve" a piece of internal software with not a single hint of what actually needed doing. After two meetings where nothing more concrete than "make it better" came up, I quietly continued working on actually achievable stuff until I left a few months later. When I checked up on my colleagues a few years later the damn thing was still in limbo.