[CLIENT/GAMEPLAY] Masteries Error - Won't Load In-Game

Bug Description: Creating a new mastery page with a label containing part/all of a champion's name produces a client error message. Following initial error message, attempts to select premade mastery pages will also result in error. Masteries will fail to load into the game following the error message in either situation.

Attempted Fixes: Restarted client (errors persisted) Cleared memory cache via CCleaner (Temporarily fixed: able to select premade mastery pages; able to create mastery page without champion name as part of label)

**Steps to Recreate: **

1. Join dynamic queue (I did with a party)
2. Select a champion (I selected Singed)
3. Create a mastery page, fill it in, and label it something related to the champion's name (I used "singed" and "singyer"; both produced errors)
4. Click "OK" on error message, return to champ select screen (Note: it will appear as if mastery has saved) 5a) Join game, masteries will fail to load 5b) Select premade mastery page before loading game, encounter same error, masteries will fail to load in-game (Optional) Restart client. Look at mastery pages and see you have a new, blank mastery page without a label. Errors will persist until clearing memory cache.