Help: Problems logging into Primavera

Hi everyone

 

I'd be really grateful for some help please!  I desperately need to get cracking on some important work today and can't get back into P5.  I get the following error message.

I had this problem ages ago and seem to recall that I just needed to clear a log file somewhere or something simple like that, but can't quite recall at this stage.  Any help to get this resolved gratefully received.

 

Thanks in advance

 

Andy