Troubleshooting hardware and software can be viewed from two different directions (like the OSI model). If the app worked yesterday, why doesn't it work today? Well, if new software was installed (known or unknown), the software layer is suspect. If new hardware, the lower layers. If neither, look back to hardware, since it is susceptible to changes in heat and electronic activity.
Finally, memory can be similar to our own memories sometimes. Only ours can't be replaced, just jogged!!
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TJW
"The only constant is change" - (unknown)
TJW
"The only constant is change" - (unknown)