Error message

• Warning: Attempt to assign property 'expire' of non-object in MemCacheDrupal->valid() (line 127 of sites/all/modules/memcache/memcache.inc).
• Warning: Attempt to assign property 'created' of non-object in MemCacheDrupal->valid() (line 130 of sites/all/modules/memcache/memcache.inc).
• Notice: Trying to get property 'created' of non-object in MemCacheDrupal->valid() (line 143 of sites/all/modules/memcache/memcache.inc).
• Notice: Trying to get property 'expire' of non-object in MemCacheDrupal->valid() (line 151 of sites/all/modules/memcache/memcache.inc).
• Notice: Trying to get property 'expire' of non-object in MemCacheDrupal->valid() (line 154 of sites/all/modules/memcache/memcache.inc).
• Notice: Trying to get property 'expire' of non-object in MemCacheDrupal->valid() (line 154 of sites/all/modules/memcache/memcache.inc).
• Notice: Trying to get property 'created' of non-object in MemCacheDrupal->valid() (line 174 of sites/all/modules/memcache/memcache.inc).