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It was happened when I saved the changes in text file in C.Basic (it is one of Calcraft files IIRC) and later when I saved other files C.Basic poped save errors occasionally and frequently as the time passed, and eventually completely unable to save the files in Storage memory. "Main memory" flash is still usable but "Storage Memory" is not. I don't know if it make sense, but I will have it a try tomorrow. My friend told me that you can try to remove the battery of the calculator and wait a few days. I'm not sure what is "unusable" mean, is it can't modified anything? or somehow the Storage memory is not accessible. May I ask you what you have done before that problem raised?
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