Hi Guys, I am getting below error(Probably Limit Exceeded or 0 recipients) from process builder. Please help me to troubeshoot this issue.

ERROR EMAIL :
Error Occurred During Flow "Route_Case_to_relevant_Queue_on_Creation": Probably Limit Exceeded or 0 recipi...

Error element myRule_7_A1 (FlowActionCall).
Probably Limit Exceeded or 0 recipients

This report lists the elements that the flow interview executed. The report is a beta feature.
We welcome your feedback on IdeaExchange.

Flow Details
Flow Name: Route_Case_to_relevant_Queue_on_Creation
Type: Workflow
Version: 11
Status: Active

Flow Interview Details
Interview Label: Route_Case_to_relevant_Queue_on_Creation-11_InterviewLabel
Current User: Rashmi (005O0000004JXSw)
Start time: 07/08/2017 12:25
Duration: 0 seconds

How the Interview Started
Rashmi (005O0000004JXSw) started the flow interview.
Some of this flow's variables were set when the interview started.
myVariable_old = null
myVariable_current = 500O000000AqkLaIAJ

ASSIGNMENT: myVariable_waitStartTimeAssignment
{!myVariable_waitStartTimeVariable} Equals {!Flow.CurrentDateTime}
Result
{!myVariable_waitStartTimeVariable} = "07/08/2017 12:25"

DECISION: myDecision
Executed this outcome: myRule_1
Outcome conditions: and
1. {!myVariable_current.EntitlementId} (550O000000053WQIAY) Is null true
Logic: All conditions must be true (AND)

RECORD UPDATE: myRule_1_A1
Find all Case records where:
Id Equals {!myVariable_current.Id} (500O000000AqkLaIAJ)
Update the records’ field values.
EntitlementId = 550O000000053WQ
Start_First_Response_Milestone__c = true
Result
All records that meet the filter criteria are ready to be updated when the next Screen or Wait element is executed or when the interview finishes.

CASEUPDATEWITHPAC (APEX): myRule_1_A2
Inputs:
caseIds = {!myVariable_current.Id} (500O000000AqkLaIAJ)
Outputs:
None.

DECISION: myDecision2

DECISION: myDecision4

DECISION: myDecision6
Executed this outcome: myRule_7
Outcome conditions: and
1. {!myVariable_current.Origin} (Web) Equals Web
2. {!myVariable_current.Case_Language__c} (English) Equals English
3. {!myVariable_current.ParentId} (null) Is null true
Logic: All conditions must be true (AND)

CASE.ARR_WEB_ENGLISH (EMAIL ALERTS): myRule_7_A1
Inputs:
SObjectRowId = {!myVariable_current.Id} (500O000000AqkLaIAJ)

Error Occurred: Probably Limit Exceeded or 0 recipients