Notice: Undefined offset: 1 in C:\wamp\www\forums\bb_plugins.php on line 126

I am working on "Unread messages indicator add-on". I have added /modify accordingly as per instruction. But I am gettin the error: Notice: Undefined offset: 1 in C:\wamp\www\forums\bb_plugins.php on line 126

And the line no. 126 is: $readTopics[$q[0]]=$q[1];

Any help to resolve this issue?

Also I am getting error: -
Warning: substr() expects parameter 2 to be long, string given in C:\wamp\www\forums\bb_plugins.php on line 47


And the line no: 47 :-

if(substr($_COOKIE[$cookiename.'_tread'], '_')==0) {

Use Compiler to compile this add-on and re-install your package, it has very difficult installation. What I could say definitely, is that it doesn't contain such error by default. There is some mistake on your end, which is impossible to determine without debugging and seeing your forum.

I don't understand.. today when I clicked on Advanced latest discussions on my forum..
I saw this error?
I didn't touch anything for long time in my forum.. I don't know what's wrong then?
on this line:



but now it's ok.. how it happens?

Please copy the error message, without seeing it hard to tell what you are about ;-)