Dealing With Unhappy & Complaining Roleplayers

First off, an ounce of prevention is worth a pound of cure. You can minimize complaints and dissatisfaction by making it clear to players from the start what kind of game they're getting into and how they're supposed to conduct themselves both IC and OOC. Check out Starting & Running Roleplays & Bringing In New Players and Setting Rules & Limitations In Your World: Why & How You Need To Do This for more tips on writing out a good, solid set of rules and guidelines for your RP.

Keep a cool head and don't give in to a knee-jerk reaction. When a player complains, your first reaction might be to get indignant - "Ugh, who is this jerk, trying to tell me I'm running my own game wrong?!" But here's the reality: As game master/admin, it's your job to provide and maintain an environment where people can have fun, and sometimes that means listening to and considering someone's complaint. Of course, not all complaints are worth considering for long. Some are positively ridiculous ("It's not fair that I can't play my angel/demon hybrid in your Star Trek RP!") and can be dismissed outright. But even so, you should still listen and find out what the player wants before dismissing it.

In any case, never try to belittle or make a player feel bad for bringing up things like this. Don't try to deflect or dodge the issue by bringing up real-life troubles you might have. (They might be a reason, but they're not an excuse.) Deal with it politely and directly - or if you're not up to it right now because of real-life issues, state that you need some time to collect yourself, but make it clear that you'll consider the issue as soon as you can. (More on what to do if you're stressed out by real life later.)

Here are a few examples of how you might handle a few complaints and questions:

Possible complaint: "This RP is boring. There's nothing to do."
Possible response: "Can you elaborate? What kind of stuff are you wanting to do here?"

Possible complaint: "I can't find anyone to play with."
Possible response: "All right. What have you done to try and get your character involved so far? What happened?" (From here, you can work out whether the player's character hasn't been proactive/accessible enough, whether old players didn't make any effort to involve the new player into the game, whether the player might have just come in at a bad time, or whether it's something else.)

Possible complaint: "Your rules are too strict."
Possible response 1: "Can you tell me what you mean? What do you want to do that the rules are keeping you from doing?" (From here, you might decide whether the rules should be followed as-are, or whether they should perhaps should be adjusted.)
Possible response 2: "I understand that these rules aren't for everyone, but that's the way things are run here. Perhaps this isn't the right roleplaying community for you."

Possible question: "I want [something that isn't what the game is about]."
Possible answer: "I see. Unfortunately, this isn't the kind of game we're playing. This game is about [game subject]. Perhaps this isn't the right game for you."

Possible question: "I want [something that isn't supported by canon]."
Possible answer 1: "I'm sorry, but this game uses canon elements only. Is there anything canonical you might consider instead? Or is there a way you could retool what you want to be canon-compliant?"
Possible answer 2: "I see. However, our game uses canonical elements only, so you'll need to stick to those. The closest thing to what you want in canon is [canon analog] - would you consider that instead?"

Possible question: "I know my OC isn't canon-compliant, but why won't you let me play her?"
Possible answer 1: "We stick to a certain canon so that everyone is on the same page with what's happened in the universe so far and doesn't get confused. Your OC would require changing significant events that both directly and indirectly affect a lot of people's characters. I get that you want to play your OC as-is, but this is how it is. If you want to play your OC, you'll have to retool her to be canon-compliant."
Possible answer 2: "Because a canon-based game is the kind of game we're playing. If you want to do something else, this isn't the right game for you."

Remember that some chronic complainers don't mean any harm - they just want to be helpful. These people aren't trying to be mean or cruel. They don't hate you, the other players, or your game. They just really, really, really want to help you and everyone else have the best roleplay they possibly can. Of course, their ideas might still be very unhelpful, or they might flood you with more complaints and suggestions than you know what to do with! Here are a few ways you might deal with these people, depending on the situation:

The player gives you no end of irrelevant suggestions/complaints: "I appreciate that you're trying to help, but this doesn't really fit our playstyle. Maybe this isn't the right community for you?"

The player gives a bunch of suggestions/complaints despite being new to the community: "I understand that you're trying to help, but you should really try to get accustomed to how this community works before trying to fix it. Most things here are done the way they are for a reason, and it's important that you understand these reasons before trying to change things."

The player gives more suggestions/complaints than you know what to do with: "I understand that you're trying to help, but all complaints and suggestions require time to deliberate and consider, and you're overwhelming us with them. Instead of making so many suggestions/complaints, pick one or two that are the most important to you, and give us time to discuss them before suggesting anything else."

The player keeps on flooding you with suggestions/complaints: "I appreciate your enthusiasm to help, but if our playstyle is so fundamentally different from what you actually want to play, this probably isn't the right roleplaying community for you."

Remember: a lack of complaints up until now don't always mean that that everyone else is happy. Sometimes, players stay quiet because they all assume that they're the only ones who are unhappy with the game. In some cases, they stay quiet because they're too afraid or demoralized to speak up. So a lone complainer might not be the only one who has a problem with the game - the lone complainer might just be the only one who actually spoke up about it.

Also, remember that even if a player is the only one unhappy with something, it doesn't mean that the player's complaint should just be brushed off. For example, if a player complains that there's nothing to do while everyone else seems to be getting on just fine, it might be that the player's character is being snubbed or ignored, or the player needs a little extra help figuring out how to get into the game. In any case, every player's wants should be given fair consideration - that's your job as GM/A. Maybe you won't be able to mesh what the player wants wants into the game, but maybe you can. Or maybe you and the player can work out a compromise.

Try getting the other players involved. If you're not sure how to solve a complaint, don't be afraid to ask your other players for their advice and opinions. If possible, see if you can make them part of the solution, too - for example, if someone is having trouble finding a character to interact with, ask the players if any of them would be willing to make any of their characters available.

And because of the aforementioned fact that players might keep quiet because they think they're the only ones who are unhappy or are afraid to speak up, it's a good idea to occasionally outright ask your players if they have any concerns, problems, or suggestions relating to the game in general.

If you're under a lot of stress that's affecting your ability to keep calm and objective, consider taking a break from roleplaying. Although roleplaying can be fun and relaxing, it is also a mentally-taxing activity. If something has stressed you out or currently demands your mental energy, roleplaying might not be the best option for you. You might feel like you're abandoning or letting down your players by taking a break, but you're really not. You're doing the best thing for yourself and for your roleplaying group. Completely breaking down on your group can lead to rifts that may be impossible to fix. Even if it happens that your game doesn't come back together after your break, it's still better for things to drift apart on peaceful terms than to have everyone leave bitter and angry at you and/or each other.

In the meantime, try to focus on other activities. Maybe watch or play something, or read a book, or focus on something more physical for awhile. Maybe catch up on some work or projects. You might also just talk to people, whether face-to-face or online. It doesn't really matter what you do, as long as it helps you.

Finally, never overlook the possibility that you might be in the wrong somewhere. We all make mistakes. Sometimes we get so caught up in what we want from a game that we overlook the wants and needs of our players. We might get so caught up in the dramas and storylines that we're interested in that we miss the fact that other players are being sidelined. We might get so caught up in having everything play out according to what we imagined that we forget that other players are entitled to have a say in what happens, too. So any time a player complains, don't forget to consider yourself and what you're doing. Take a look at When A Game Master Or Roleplay Admin Might Be Power-Tripping - And What To Do About It to get an idea of what to watch out for in yourself.