1756 analog module calibration is a procedure you have to follow until the end.
You get prompted to connect a voltage or current source (input modules), or a measuring device (output modules) for each channel, recording results as you go.
Your module shows "Error" on all channels because someone, sometime, pressed the "Start Calibration" button, and didn't complete the calibration steps. The "Error" is a calibration process error, not an error with the module's current operational state.
Do not be concerned about this, none of the current gains and offsets (as shown) will be updated to new calibration values until the whole of a calibration process is successfully completed. To "resolve" it (which as I say you do not need to), you would have to successfully complete the calibration process, for which you will need a precision voltage source. Unless you have one, you can buy, or hire, but probably not cheap. In general, unless you work in a regulated industry, no-one bothers with re-calibration, and use the module for the whole of its working life with the factory calibration.
The date that the module was last successfully calibrated is stored in the module, and is shown on that tab you posted.
For your problem that one analog input is reading OK, and another is not, do the following....
Check the configuration settings for the non-working channel. Is it set to the correct input type. Are the scaling parameters correct., etc.
Check (with a voltmeter) that you are actually getting a voltage on the input of the channel that is not reading. (NB. a mA Input type will have a 250 ohm resistor across the input, such that 4 to 20mA will be 1 to 5V). If you have a voltage within range, and the channel is not reading correctly, then the channel may be faulty.
If the above checks out OK, you can try moving the non-working input to another unused channel.
If you see no voltage on the input, then your external wiring is at fault. Has it been fused ? Some people put a fuse in analog inputs, especially if it is a current input.