1) Welcome to the party!
2) Help us help you:
when you post, please post your entire configuration including (but not limited to) your installation method and vicidial version with build.
this IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "from scratch" you must post your operating system and should also post the .iso version from which you installed your original operating system.
Similar to This:
Vicibox X.X from .iso | Vicidial X.X.X-XXX Build XXXXXX-XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation
3) Push the (?) next to the [Browse] button when you are selecting your list for download. That help page has a list of 23 fields. Load a file with those 23 fields as "headers". then load your data directly below those fields. Then save the file as "Text: Tab Delimited". Then your list should load with no problems. (But do remember that if there are dupes, and you select the dedupe options, vicidial WILL catch and kill the dupes and call them bad leads).