I just flew from Brooklyn to Berlin and found a snafu using my laptop for a time-sensitive film project. En route in Dusseldorf, I experienced a distinct slow speed of my laptop to process simple commands like opening a folder or shutting down. It was running just fine until I opened the laptop again to continue writing a MSWord document, suddenly everything was slow and every click resulted in the cycling of the colored spindle. There was no special or extra bump on the laptop to cause problems. The colored spindle just rotates for several minutes before engaging in an assigned task. I went through three tests like resetting SMC, NVPRAM, and Apple Hardware Test, all of which show no problem to the computer from these tests. Disk utility shows no errors or repairs needed. A system report shows no errors or flags, and kernel task is under 2% of CPU and uses 834MB of Disk. The first time I did it, I did notice the laptop was very responsive from the smc test but the problem of slow lag occurred a few moments later. There are no applications open, I performed malware tests using Avast software. The internal OWC 6G extreme pro 480GB SSD still has 90GB free. This SSD is 3.5 years old. Specs: MBP 9,2 13 " Mid -2012 Intel Core i7 Memory: 8GB Processor: 2.9 GHZ OSX: 10.11.6 Any ideas to fix the lag?