Sitecore logs are showing lot of these messages: WARN The current user cannot be resolved from the authentication cookie. The cookie will be removed.
Ex:
Line 556: 1820 07:14:48 WARN The current user cannot be resolved from the authentication cookie. The cookie will be removed.
Line 1680: 6612 08:02:06 WARN The current user cannot be resolved from the authentication cookie. The cookie will be removed.
Line 1681: 6916 08:02:06 WARN The current user cannot be resolved from the authentication cookie. The cookie will be removed.
We are using mixed authentication : Asp net membership provider + Sitecore virtual user. We recently upgraded from Sitecore 7.2 to Sitecore.NET 8.1 (rev. 160519) and are using Mongo DB as well for gathering Analytics data.
Any suggestions to identify the issue? I verified on the server and there aren't any app pool recycles when this happened.