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ANSWER:
Remove a Custom Relationship field
or
Increase the limit to 50.
The 'soft' limit is 2540. If you are currently using 25 40 custom relationships then you can submit a request to Salesforce to increase the amount to the 'hard' limit of 50.
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1 on the Opportunity Object
1 on the Activities (Task, Event) Object
1 on the Account Object
NOTE:
If you are already at 50 custom relationships, you must remove an unused or deprecated custom relationship on the Activity Object to install ClosePlan.
Please review your Custom relationships to find one to free up.
Troubleshooting
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The client clearly had 37 Custom Relationship Fields on their Opportunity Object, but the install failed.
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Here is a report you can use to find all the Custom Relationship Fields (except those in the ‘Deleted Fields’ list!)
Create a New Report Type
Create a Report to find all Custom Relationships
In the Client’s Org, go to Setup
Search: Report types
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Go to Setup > Report types > click the ‘New Custom Report Type’ button
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For Primary Object
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select Entity Definitions
Report Type Label and Name: Custom Relationship Lookup
Description: As needed
Store in Category: Other
Select "Deployed"
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> Next
Click "Click to relate another object' > ‘Field Definitions’ and select
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Each "A" record must have at least one related "B" record.' > Save
2) Create the Report
Create a new report and select Custom Relationship Lookup report type
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Group Rows:
Qualified API Name (from the Entity Definition table)
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Show Me: All entity definitions
Created Date: All Time
Is Customizable? equals True
Qualified API Name (from 'Field Definition' table) contains "__c"
Data Type contains lookup
Click Save & Run
Save the Report to the ClosePlan folder. If it does not exist, create it.
Your report will look similar to this:
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