This issue was reported manually by Chiana.
It already has 2 duplicates 


Build: NetBeans IDE Dev (Build 201012050001)
VM: Java HotSpot(TM) Client VM, 17.1-b03, Java(TM) SE Runtime Environment, 1.6.0_22-b04
OS: Windows Vista

User Comments:
Chiana: Just tried it again to be sure...

Chiana: Created a stub class since the original class was renamed, I noted problems with loading old data.

Background:
The original class recieteLine was moved to an other package. Data was saved serialized in an SQL table.
Because of problems reloading that old data (ClassNotFound exception thrown) I decided to create a stub-class with the old name;
package reciete;
public class recieteLine extends recieteLine{}

This is because in my experience NB shows a dialog if classnames are ambiguis when using fix-import but latley it has started throwing this (and similar) exceptions instead.
Oh, yes, exception was thrown when invoking "fix import".




Stacktrace: 
java.lang.StackOverflowError
   at java.util.regex.Pattern.atom(Pattern.java:1952)
   at java.util.regex.Pattern.sequence(Pattern.java:1834)
   at java.util.regex.Pattern.expr(Pattern.java:1752)
   at java.util.regex.Pattern.compile(Pattern.java:1460)
   at java.util.regex.Pattern.<init>(Pattern.java:1133)
   at java.util.regex.Pattern.compile(Pattern.java:823)