"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: Insert failed. First exception on row 0; first error: STORAGE_LIMIT_EXCEEDED, storage limit exceeded: []"

Getting this error message when trying to check challenge. This is Automate Basic Business Processes with Process Builder module in Trailhead. I followed the steps suggested by people to check storage from system overview area. I checked that and found I have lots of storage available. Only 350 KB out of total possible of 5MB, which is only 6% of total availa storage. so 94% is free.

When I click on 350 KB and check storage usage, everything looks okay except File storage which is 112% used. Content bodies have used 99% of available storage.

Can somebody please advise what should I do. and if I have to reduce file storage how can i do that.

Thanks in advance.

"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: Insert failed. First exception on row 0; first error: STORAGE_LIMIT_EXCEEDED, storage limit exceeded: []"

Getting this error message when trying to check challenge. This is Automate Basic Business Processes with Process Builder module in Trailhead. I followed the steps suggested by people to check storage from system overview area. I checked that and found I have lots of storage available. Only 350 KB out of total possible of 5MB, which is only 6% of total availa storage. so 94% is free.

When I click on 350 KB and check storage usage, everything looks okay except File storage which is 112% used. Content bodies have used 99% of available storage.

Can somebody please advise what should I do. and if I have to reduce file storage how can i do that.

Thanks in advance.

Help: I have created a Validation which will block the insertion of a contact if the contact is related to an account and has a mailing postal code (which has the API Name MailingPostalCode) different from the account's shipping postal code (which has the API Name ShippingPostalCode).
I tested the validation and I know it works because it gives the correct error message for this scenario however I am recieiving this error from Trail Head when I click on the green Check Challenge button :

There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Insert failed. First exception on row 0; first error: STORAGE_LIMIT_EXCEEDED, storage limit exceeded: []

2) I checked Data Management and I have a lot of space for creating a contact (1% or 99% free space)
For accounts I am at 93% full but I am not creating another account.

IS it the account percentage that needs reducing even though I am not creating another Account obejct at 93%?  Thanks for your help on this.