Hi I am currently progressing on developer trailhead and i am currently on Formulas and Validations >> Using Formula Fields. I am not able to identify what exactly i am missing here.

"Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Delete failed. First exception on row 0 with id 001b000003Jz2fSAAR; first error: DELETE_FAILED, Your attempt to delete Test Account could not be completed because it is associated with the following cases.: 00001053 : []"

can someone help me on pinpoint what it might goes wrong?

​Thank you!

Hi I am currently progressing on developer trailhead and i am currently on Formulas and Validations >> Using Formula Fields. I am not able to identify what exactly i am missing here.

"Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Delete failed. First exception on row 0 with id 001b000003Jz2fSAAR; first error: DELETE_FAILED, Your attempt to delete Test Account could not be completed because it is associated with the following cases.: 00001053 : []"

can someone help me on pinpoint what it might goes wrong?

​Thank you!

Hi I am currently progressing on developer trailhead and i am currently on Formulas and Validations >> Using Formula Fields. I am not able to identify what exactly i am missing here. The steps to be followed are
The formula should be on the Case object.
The formula should be of return type Number.
The formula should be named 'Days Since Last Update' and have a resulting API Name of 'Days_Since_Last_Update__c'.
The formula should return the number of days between the account’s Last Activity Date and today.

I have created a custom obj Case and Added a Formula field with the name as mentioned. Formula i have used in Today () - LastActivityDate . But when i check my activity it display error "The 'Days_Since_Last_Update__c' does not exist "..

My first confision in the steps is "The formula should return the number of days between the account’s Last Activity Date and today.". what does ACCOUNT'S Last Activity Date means here .. do i need to somehow relate Case and Accounts object first  ?

Any help/suggestions please ?