crash fatal error

Hi everyone,
I have created a new book yesterday and while assiging formats and numbers to various documents updated this book several times. Today, when adding the generated files and updating those Frame crashes and reports a fatal error. I have found out that it is cause by either my index or index of figures. Any ideas on how to fix this? The file is generated but cannot be updated. Crash report files are never to be found so I have stopped to look for them.