As digital libraries make the dissemination of research publications easier, they also enable the propagation of invalid or unreliable knowledge. Examples of relevant problems include: retraction and inadvertent citation and reuse of retracted papers; propagation of errors in literature and scientific databases; non-reproducible papers; known domain-specific issues such as cell line contamination; bias in research datasets and publications; systematic reviews that arrive at different conclusions about the same question at the same time. The digital environment facilitates broad interdisciplinary reuse beyond the originating scientific community; thus, marking known problems and tracing the impact on dependent and follow-on works is particularly important (but still under-addressed). Further, context-specific information inside a paper may not be immediately reusable when extracted by automated processes, leading to apparent contradictions. Current mitigating approaches use the underlying reasoning for information retrieval, develop new infrastructures analyzing the reasoning or certainty of statements, or use visualization to highlight possible discrepancies.