error when sorting list

error when sorting list

Hi! I am trying to retrieve the last 5 participants, introduce their names and performances in a list and then sort them and show the ranking in an HTML view. My code is the following:

1. <tr class="zc-row-header">
2. <td class="zc-viewrowheader">Name</td>
3. <td class="zc-viewrowheader"> Correct answers</td>
4. </tr>
5. <%index_list = {0, 1, 2, 3, 4};%>
6. <%name_list = {};%>
7. <%performance_list = {};%>
8. 
   
9. <%for each index1 in index_list
10.     {
11.         row  =  Session_2_Water_and_jar  [ID != 0] sort by  Added_Time desc range from (index1  +  1) to (index1  +  1);
12.         name_list.add(row.Name);
13.         performance_list.add(row.Performance);
14.     }%>
15. 
    
16. <%for each index2 in index_list
17.     {%>
18. <%max1 = 0;%>
19. <%max_index = 0;%>
20. <%for each index3 in index_list
21.         {%>
22. <%if (max1  <  (performance_list.get(index3)).toLong())
23.             {%>
24. <%max1 = (performance_list.get(index3)).toLong();%>
25. <%max_index = index3;%>
26.                                                                                                 <%}%>
27.                                                                 <%}%>
28. <tr class=zc-viewrow>
29. <td><%=name_list.get(max_index)%></td>
30. <td><%=performance_list.get(max_index)%></td>
31. <%name_list.remove(max_index);%>
32. <%performance_list.remove(max_index);%>
33. </tr>
34. 
    
35.                                 <%}%>

It was working perfectly for the past 2 weeks but this morning I started getting the following error:

Error details:

Error occured while executing the script.

Unable to evaluate if/while Condition

If I delete the last line, the one with <%performance_list.remove(max_index);%> I get the error:

Error details:

Error occured while executing the script.

'get from list' operation failed as the index is greater than the list size

I checked the value of the index and it is definetely not greater than the list size. Could somebody please help me? What am I doing wrong and how come it worked so far?