İlker GELİR 

The error message you've shared indicates a problem with the spell check function. The specific error message 'RPC sunucusu kullanılamıyor. (HRESULT özel durum döndürdü: 0x800706BA)' suggests that there is an issue with the Remote Procedure Call (RPC) server being unavailable.

No simple answer for this but these may be the most likely causes of this error:

1. Firewall/Antivirus Interference: Sometimes firewall or antivirus software can block the RPC traffic which is necessary for Trados Studio's spell check function to communicate with the necessary services.

2. Software Conflict: There might be another application that is conflicting with Trados Studio's operations. This could be especially relevant if you've recently installed new software.

3. Corrupted Installation: The installation of Trados Studio or its spell check component might be corrupted. Reinstalling Trados Studio could resolve the issue.

4. Updates Required: Your Trados Studio or the component it relies on for spell checking might need an update. Check for any available updates for Trados Studio and install them.

5. Compatibility Issues: If you're running Trados Studio on an operating system or under conditions that it's not fully compatible with, this could cause the error.

Certainly posting a screenshot and nothing else to go on isn't helpful.