Could not complete the Open Session command because while translating Memory List

[Sikin]

Hello all

Been working on my tracks since upgrading to a new pc a few months ago and everything seems great, i was working on this certain session last night, everythings fine, saved it, turned my pc off went to bed and then woke up launched protools again. when i load my session file it begins to open but then it reverses and says "closing". then this message appears. does anyone know why i am getting this message?

""Could not complete the Open Session command because while translating Memory Location List""

Very frustrating. so i have restarted my pc and tried 2 more times but same again.