Could someone help clarify the way to utilize these steps in order to fix my sharepoint configuration. It currently stops at stage five with the error: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. It's not clear which parts I insert with my own information and what is just copied and pasted.

Step 1: Enable search admin timer job via PowerShell.

 Enable-SPTimerJob job-application-server-admin-service  
Step 2: Update the account running Osearch15/Hostcontroller services using:
$password = Read-Host -AsSecureString  
Set-SPEnterpriseSearchService -IgnoreSSLWarnings $true -ServiceAccount <domain\Account> -ServicePassword $password  
Step 3: Make sure the account you use to configure the application is a member of the WSS_WPG group and the group has full control over the following path.
C:\Program Files\Microsoft Office Servers\15.0\Data\Office Server\Applications.  
Step 4: Run following powershell to check if AdminComponents has value returned.
$ssa = Get-SPEnterpriseSearchServiceApplication 'Search Service Application'  
Get-SPEnterpriseSearchAdministrationComponent -SearchApplication $ssa  
If not, set as following:
$varInstance = Get-SPEnterpriseSearchServiceInstance -local  
set-spenterprisesearchadministrationcomponent –searchapplication $varSearchApp –searchserviceinstance 
			 
Hi @Tevon ,
Thank you for your description. Regarding your question, there may be some things I don't understand and I want to confirm with you.
 Did you get the error message "System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation." when you executed the following statement?
$varInstance = Get-SPEnterpriseSearchServiceInstance -local set-spenterprisesearchadministrationcomponent –searchapplication $varSearchApp –searchserviceinstance
 Did you refer to a link for this step? Could you please send it to me for reference test?
 What function do you want to achieve in the end, can you describe it in detail?