I cannot type some characters or they appear in an unusual way.
This can happen on certain OS/locale/JDK configurations. To find out whether it's a NetBeans or JDK issue, try to use the Notepad from JDK demo. It is located in $jdk_dir/demo/jfc/Notepad. You can launch it from this directory by executing:
java -jar Notepad.jar
Then try to type in the characters you were not able to write in NetBeans. In case you can write them, it is a NetBeans issue which should be reported in Issuezilla. Otherwise it's a JDK bug which we cannot fix (but you can still let us know and we may file it against JDK).
Setting the encoding in Linux
You can try the previous procedure setting the locale explicitly before launching java. For example:
LC_CTYPE=en_US.UTF-8 java -jar Notepad.jar
Applies to: All NetBeans versions