Will not read plates at any wavelength outside of 555-600nm

If I try to read at any wavelength outside that range, I get the following error message in SoftMax Pro software; "The last command could not be completed because of an instrument problem: Measurement aborted. The instrument will be temporarily unavailable during reset." The plate reader also won't read outside that range if try reading manually without remote software. Any suggestions or help?

Equipment: SpectraMAX 340PC