@polskifacet the error is ok, it’s due to the internal working of LittleFS. About the screen: are you sure, it’s a 0.96″? You can try switching to SH1106. The lib is the same as in the original FW and Ja.Carer’s fw… other thing you can try, is to change the OLED lib’s version in platformio.ini (4.4.0 is the latest ). Cabeling is ok? PIN21 = SDA PIN22 = SCK is the I2C