Players of Marvel Rivals are unable to queue into the game due to an error code 2103, Operation Frequency Too High, and this error seems to be impacting a sizable player base across several servers located in North America, Asia, and Europe.
It is clear that the error is not limited to one platform as console players are reporting the same. Being unable to queue, Marvel Rivals’ active player count is going significantly without players finding a consistent fix and a few lucky players can queue without any errors.

NetEase employee rivals_james has acknowledged on the Rivals’ official Discord channel that resolving the issue is a “top priority” and that many gamers are having problems. Players of Marvel Rivals will have to wait for developer NetEase to update their servers to fully address the problem before they can queue once again.
Server outages are common in multiplayer games while it may be frustrating if you have been waiting the whole day to play the game just to find your plans foiled by some random server error, rest assured the developers will drop a patch ironing out the issue in no time.