In order to resolve this issue we'll need to remove a folder from your computer.
Please ensure that both iMindMap 6 and the iMindMap 6 Pre-Loader are closed before continuing. The Pre-Loader can be closed by viewing the hidden icons in the bottom right corner of your operating system on the Windows taskbar, right clicking the iMindMap 6 icon and selecting Exit.
The folder to delete is located in the following directory:
Please note that the ProgramData Folder is different from the ProgramFiles folder. The ProgramData is a hidden folder so there's a couple of ways we can get to it:
1) Type %PROGRAMDATA% into the search box on the windows Start menu and hit enter
2) Open 'Computer' from the start menu and type (or copy and paste) C:\ProgramData\ThinkBuzan\ into the top bar where it says computer
Once you've got to C:\ProgramData\ThinkBuzan\ you should be able to see the imindmap_cache6 folder and delete it.
After deleting the imindmap_cache6 folder please restart iMindMap 6.
You can also find a video tutorial which explains the above process on the following web page:
This should hopefully resolve the issue.