FSLogix - getUserToken (An attempt was made to reference a token that does not exist.)

Question

Some of my users get sometimes their profile stuck. When searching into fslogix logs, i find this : getUserToken (An attempt was made to reference a token that does not exist.)
No reference of this error on Google.. Not even 1.

Last user having this problem got a white screen but not sure that's linked to this error knowing the fact that another error about udwm.dll was also present.