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I am using the last one (7.1.2).
I was trying to open files from Mega cloud app. Even a simple text file with a couple of characters downloaded from there gets failed to be edited after import. But the same file is read and written well in other editor apps. From the other side, when I import files created in those editors to Textastic, all works well as it should (chain import "Mega->some editor (even modified here)->Textastic" still failes).