User tries to install our package on his org and gets an “Installation failed” error.
There can be multiple reasons for this issue. For example,
1.The user does not have appropriate access level for installing an app.
2.The Un-managed custom object tab already exists and the package upgrade cannot create another tab
3.Trying to install the application on the Professional Edition or an earlier version of Salesforce.
The possible solutions to resolve this issue is provided below:
1.Refer the Salesforce help document ( URL mentioned below) for details on the access level that is required to install an app – https://help.salesforce.com/articleView?id=distribution_installing_packages.htm&type=5
2.If you had created a tab for Message_Object_Config__c object in an older version and then tried to upgrade the customer to a latest version (1.50+), then you will get this error. In order to resolve it, do the following:
a. Under Setup, click Tabs and then click Delete next to the object name. The Salesforce tab is successfully removed.
b.Re-install the package .
3.Refer the URL mentioned below: