Error Invalid TLV record when opening a crystal report for drill arounds.
gsusnme (BOB member since 2010-04-28)
I know this is an old post but I had the same symptoms which I have just resolved so am posting my findings.
In my case a schedule had been set up and a mail sent with an attachment either without an extension or with the wrong extension. That is the extension settings did not match the format settings.
It turned out that this was caused because the file I was trying to open was not a Crystal Report (.RPT) file but an Adobe Acrobat (.PDF) file. Opening the file in Adobe Reader worked.
cntoms 
(BOB member since 2010-07-02)