I'm not able to search in Multiterm. When I try, I get the error "Object reference not set to an instance of an object". As you can see, part of the Terms window is "hidden" (white).
You don't say which version of MultiTerm you are using.
If it's 2017 for example, try the following:
Close MultiTerm and Studio.
In Windows Explorer, navigate to the following:
c:\Users\[USERNAME]\AppData\Roaming\SDL\SDL MultiTerm\MultiTerm14
Delete 'MultiTerm14' folder. If you don't like deleting things, rename it - 'MultiTerm14Old' for example.
Restart MultiTerm and the 'MultiTerm14' folder will automatically be regenerated.
If you're using MultiTerm 2015 then the folder to delete is 'MultiTerm12', etc.
This may be enough to cure the problem.
If not, try running a Windows Repair of MultiTerm and Studio via Control Panel.
Do you know how to reorganise a termbase? That is automatically prompted for if it's required whether you're using MultiTerm directly or via Studio. Periodically reorganising helps the termbase run more smoothly.