If you are unable to launch or login to Curse Client v5, it is often due to a corrupt or outdated Microsoft.Net installation. Before trying these options please try this guide first.
Delete your 2.0 folder
Start by cleaning out your 2.0 folder. Close down the Curse Client completely the proceed.
You will want to delete your 2.0 folder. This is a fairly easy task to do. If you are unsure how to do this you can check out our guide on how to do this process.
Note: You may want to also clear out your computers Temporary files as well. You can use a program such as CCleaner to help you with this.
If this also doesn't work please proceed with the following.
How to Fix a Missing or Corrupt .Net Install
Curse Client v5 requires Microsoft.Net Framework 3.5 Service Pack 1. Ideally, this is automatically installed for you by the Curse Client installer, if it is missing. In some rare cases, this process can fail, and .Net must be installed manually.
How to Install the .Net 3.5 Client Profile
Curse Client 5 uses a subset of the Microsoft.Net Framework, called the Client Profile.
This can be installed from: Microsoft .NET Framework Client Profile Online Installer
How to Install the .Net 3.5 SP1
If this installation fails, you may need to run the full Microsoft.Net Framework installation.
This can be installed from: Microsoft .NET Framework 3.5 Service Pack 1
How to Cleanup a Corrupt .Net Framework
If this installation fails, you may have to run the Microsoft.Net Cleanup Tool. This tool will remove .Net from your PC, and allow you to do a fresh .Net framework installation.
This can be downloaded from: .NET Framework Cleanup Tool
Once there, click the Download link close to the top of the page. Make sure you reinstall .NET Framework in numerical order (i.e., 3.5 > 4.0 > 4.5 ).