There is nothing “wrong” with the RSV.
In 1966 it became the first Protestant Bible to receive an imprimatur by ecclesiastical authority. While no alterations were made to the Old Testament, several were felt required for a few renderings of the New Testament (and informative notations added throughout) before it was deemed suitable for Catholic use (Catholic books were also added).
Even though there has been a major revision to the text as the NRSV and the ESV, most scholars, Protestant and Catholic, acknowledge the RSV for its accuracy and scholarship. It was the first English version to introduce scholarship based on what had been learned from the discovery of the Dead Sea Scrolls. It is a great choice for any Christian of any denomination, and the original Catholic edition has been in use up to the date of this writing by the Holy See when interpreting Bible readings into English during radio and television broadcasts from Masses held at the Vatican.
There are several things to note:
The RSV uses archaic pronouns, such as “thou, thee, thine,” etc. in addressing God.
Even more has been learned from the Dead Sea Scrolls that has added much to accuracy in renditions (and even clarified and added missing parts to texts such as in 1 Samuel and Tobit). You won’t find that in the RSV.
Some Catholic language, such as “amen, amen” and “magi” are rendered along the lines of “most truly I tell you” and “wise men,” etc.
The RSV was originally hated and even burned by conservative Christians due to the fact that Isaiah 7:14 used the expression “young woman” instead of “virgin.” It also renders a few prophecies (such as Genesis 22:18 and Psalm 16:10) with language that some allege obscures their Messianic typology. It was due to these matters that conservative Christians developed other versions, most notably the NIV and the ASV in response.
The RSV-CE 2nd edition might be a better choice if you prefer the archaic pronouns to be dropped. And while you won’t find unique Catholic expressions like “amen, amen I tell you,” changes have been in the text to make it comply with what one hears in the Liturgy, both in Old and New Testament readings.