Hey all! I am having an issue with validating rules. My Trailhead playground seems to support Account & Opportunity validation. However, it cannot check the opportunity validation rules even tho it is saved. Does anyone know how to fix this? Thanks!

 It sounds like the validation rule is saved but not being recognized during the check. Make sure the rule is active, the error condition formula is correct, and that the challenge test data actually triggers the rule. Sometimes Trailhead requires very specific field names or conditions to match their criteria. If everything looks right, try refreshing the playground or creating a new one, as playground glitches can prevent the checks from running properly. This usually resolves the issue.