Since Friday (2-Sep-22) a number of c9 clients have reported c9 server down.

The common problem is antivirus software malwarebytes. It appears to be falsely identifying parts of c9 as being malware.

This is a reasonably common occurrence with antivirus software, known as a false positive. It is the first time this has happened wholesale with malwarebytes although.

The easiest/quickest repair to date requires changes to malwarebytes on server computer.

• Add the c:\c9db\ folder into malwarebytes exception list
• any files in malwarebytes virus fault which are in c:\c9db\ : restore them.
• restart computer

At time of writing, I am aware of 4 of our clients who have been impacted so far. The above repair worked for all of them.

As always contact support if still experiencing issues. Also consider using something other than malwarebytes. We consider the default AV built into windows, windows defender, generally adequate. It is difficult to make recommendations on antivirus, they are by design blunt and imperfect instruments: they generate false positives like this one, or false negatives (fail to detect an actual nasty), and there are plenty of actual cases where the AV software itself weakened security of the computer. So we are and always have been reluctant to give advise here, but internally, for windows computers we have at c9 we use windows default AV.