If your server is lagging or crashing
There are many reasons why your server could be lagging or crashing
The first thing you should check is if your RAM and/or CPU is maxed out in your multicraft console, if one or both of them are maxed then you either do not have enough RAM for your server or you have conflicts/corruption in your server.
Note: If you see "failed to copy jar file" at startup this can be ignored, this is caused by the way multicraft works.
To find out if there are conflicts (normally cause by plugins), look in your log files for errors. The log files will be in your main directory or in a folder named logs as a ".log" file. (like latest.log). If you find errors you need to fix or remove the plugins causing the errors. When you find the error look for "caused by", this should tell you why the error happened. If the "caused by" does not list an obvious fix (like a missing dependency) you can do a google search for it, this will often lead to the fix within the first few search results.
Corruption (corrupt chunks) can be a bit harder to find and fix. Corrupt chunks are often caused by large server edits with worldedit or not having enough RAM for your server. One of the ways to find corrupt chunks is to see if it only happens when a specific person is playing, if this happens you can try to remove the chunk where that person is. With worldedit you can use /chunkinfo to find the name of the chunk file. Stop your server and go into your server files for that world, under region then backup and remove the file. You can also download your world directory and then delete if from the server it to see if it is that world causing the problem. If after a server restart the lag is gone, you know that that is the cause of the problem.
If you do not have any errors or corrupt chunks and your RAM is still always over 100% then you most likely do not have enough RAM assigned to your server.
To upgrade your server see this article: https://vahosting.net/knowledgebase/16/How-do-I-upgradeordowngrade-or-cancel-my-service.html
Lag can also be caused by connection to the server.
We do our best to make sure that everybody can connect to our servers with little to no issues, however it is impossible to have a perfect connection from everywhere in the world.
Is the lag only happening to specific people or everybody? If it is only happening to 1 or a few people then they are having connection issues to our servers. This could be caused by their provider or a connection between us and them, in most cases there is not much we can do about this issue. They should call their internet provider and see if there is an issue on their end.
If you still have issues with your server, we will be happy to help. Put in a support ticket, include the server you are having problems with, a brief description on what the issue is and what you think caused it.