the error i am getting is

Unable to make this formula automatically derived because it is used in the following roll-up summary field(s): Account.Investment Asset Rollup. To continue, remove any references to derived values such as the current date, current user, or user-role

Error: Invalid Data.
Review all error messages below to correct your data.

i am haveing an problem in my formula field i am not able to put the advance fromula in my formula field so 

what should i do to  remove this error 

following is  my custom objects(Investment_Asset__c) in which i have to give formula to TotalAsset__c

Allocated_Amount__c	               Roll-Up Summary (SUM GoalInvestmentAssetAssociation)
AMC_Name__c	                       Lookup(AMC Name)
Entity__c	                       Master-Detail(Account)
Face_Value__c	                       Number(15, 3)
fixedIncomesValue__c	               Formula (Currency)
Fund__c	                               Lookup(Fund) 
FundValue__c	                       Formula (Currency)
Maturity_Date__c	               Date
Maturity_Value__c	               Number(18, 0)
Monthly_SIP_Amount__c	               Currency(18, 0)
Remove_Checkbox__c	               Checkbox
Scheme_Name__c	                       Text(40)
Scheme_Type__c	                       Picklist
Script_Name__c	                       Text(40)
SIP_Date__c	                       Date
Stock_Value__c	                       Formula (Currency)
Total__c	                       Currency(18, 0)
TotalAsset__c	                       Formula (Currency)
Units__c	                       Number(15, 2)



another custom object which is rollupSummary is GoalInvestmentAssetAssociation__c in this i have
allocated__c	       Percent(16, 2)
Allocation__c	       Number(16, 2)
Goal__c	                Master-Detail(Goal)
GoalYearValue__c	Number(16, 2)
Investment_Asset__c	Master-Detail(Investment Asset)

 your help would do a lot of good for me