I was able to clear the error by removing NFS related modules.
I started by removing nfs, fscache, and nfs_acl. This cleared the error.
Second time, I only removed the nfs module and the error did not clear.
Third time, I removed nfs and fscache and the error did not clear.
Forth time, I removed nfs and nfs_acl and the error did not clear.
Firth time, i removed nfs, nfs_acl and fscache and the error cleared again.
(nfs_acl and fscache uses the nfs module, so nfs had to be removed each try)