Try using SUDO . The MAN page for escputil also says this error as a known bug, try retyping the command once again that should resolve the issue.
USB-connected printers sometimes fail to identify or return ink levels.
You may have to repeat the command. This is probably a timing issue in
escputil, not a flaw in the printer.
Anything requiring bidirectional communication with the printer (iden-
tify, ink levels, or head alignment without specifying the printer
model) requires read/write access to the printer port (for example
/dev/lp0). This may require these operations to be performed as root.
In addition, kernel support is required for bidirectional communica-
tion. For Linux version 2.2, CONFIG_PRINTER_READBACK should be
enabled; this is called CONFIG_PARPORT_1284 on 2.4 and later kernels.
If the printer is performing self-test or head cleaning on power up,
the identify and ink level commands will time out, although the printer
successfully receives the command. The command will need to be reis-
sued when the printer is quiescent.