An author from Spain (María de los Ángeles Oviedo García) wrote the article "Journal citation reports and the definition of a predatory journal: The case of the Multidisciplinary Digital Publishing Institute (MDPI)", in which she concluded that MDPI journals (she analyzed 53 journals indexed in WoS) are predatory. The article was published in Research Evaluation on August 11, 2021.

Already on August 19, 2021, MDPI published a comment. They pointed out that open access is sometimes misunderstood and confused with the current debate about predatory publishing practices. They raised several concerns about the analysis presented in the article, including MDPI bias, as well as concerns about data accuracy and the robustness of study methodology.

In September 2021, Research Evaluation published a text stating that they are investigating. This text can still be seen on the Scopus journal page: The journal and publisher have been alerted to concerns about this article, and an investigation is in progress. In the interim, we alert readers that these concerns have been raised. © The Author(s) 2021. Published by Oxford University Press.

The article was retracted and updated to soften the findings, but the publisher was not happy. The journal reported (April 2023) that the original version of this article was withdrawn, and a revised version was published instead to allay concerns about the article’s conclusions. The conclusions in the updated article are based on the sources cited.

However, MDPI expects more details to be made public for readers to understand why this article was retracted and corrected. They also question the handling of this retraction/correction by Oxford University Press (journal publisher) as it is contrary to COPE guidelines and standard practices.