Steps:
1. Navigate to System->Dial plan. Click on adding a new International dial rule from the drop down menu

2.Add the following dial rule :
Enabled : Yes
Name : I_D3
Permission : None
PSTN prefix : 1
Long distance prefix :1
Area code : 10, 11, 12, 137, 138, 1801, 1802, 1803, 1804, 1805, 181, 182, 183, 184, 185, 186, 187, 188, 189, 19, 32, 500, 501, 90$
External number length : 10
Gateway : G1
 
3. Click on Apply .

Excepted : Should give an error message " Please enter a comma-separated list of numbers, for example: 508, 212, 333"

Actual : When clicked on Apply the process slows down and then again when clicked on Apply the exception is given.
 
Attachments :
1. Exception.txt
2. Exception_snapshot