Expected list-like value, got string - selenium

Question

I have written a keyword which calls a sub-keyword. Now the sub keyword is returning two values which I am trying to store it in an array assigned to main keyword. When I log to console the returned values, it gives an error message saying - Expected list-like value, got string
I have tried the below workarounds(failed):
1. Attempt1:
#{Items1} Run keyword if '${INACTIVEStateCount}'!='0' INACTIVE OTOID selector ${StateCount}
Log To console Values are ${Items1}
2. Attempt2:
#{Items1} Run keyword if '${INACTIVEStateCount}'!='0' INACTIVE OTOID selector ${StateCount}
${Items2} Create List #{Items1}
Log To console Values are ${Items2}
Main keyword:
#{Items1} Run keyword if '${INACTIVEStateCount}'!='0' INACTIVE OTOID selector ${StateCount}
${Items2} Create List #{Items1}
Log To console Values are ${Items2}
SubKeyword:
INACTIVE OTOID selector
[Documentation] Used to select Inactive OTOIDs
[Arguments] ${StateCount} ${LocatorWaitTime}=${defaultWait time}
:FOR ${INDEX} IN RANGE 1 ${StateCount}
\ ${Check}= Run keyword and return status Page should contain element xpath=//*#id='lookupFiberDetailsResult']/table/tbody/tr[${INDEX}]/td[4][text()='INACTIVE']
\ ${OTO_IDStatus} Run keyword if '${Check}'=='True' Get Text xpath=//*[#id='lookupFiberDetailsResult']/table/tbody/tr[${INDEX}]/td[4][text()='INACTIVE']
\ Log to Console Loop${INDEX} - OTOID:${OTO_IDStatus}
\ ${OTO_ID} Run keyword if '${OTO_IDStatus}'!='None' Get Text xpath=//*[#id='lookupFiberDetailsResult']/table/tbody/tr[${INDEX}]/td[2]
\ ${LineIdentifier} Run keyword if '${OTO_IDStatus}'!='None' Get Text xpath=//*[#id='lookupFiberDetailsResult']/table/tbody/tr[${INDEX}]/td[1]
\ Run keyword if '${OTO_IDStatus}'!='None' Log to Console OTOID is: ${OTO_ID}
\ Run keyword if '${OTO_IDStatus}'!='None' Log to Console OTOID is: ${LineIdentifier}
\ Run Keyword If '${OTO_IDStatus}'!='None' [Return] ${OTO_ID}
\ Run Keyword If '${OTO_IDStatus}'!='None' [Return] ${LineIdentifier}
\ Exit For Loop if '${OTO_IDStatus}'!='None'
What I intend to achieve:
I am making the sub-keyword return two values: OTOID and LineIdentifier and store it in an array. And then use these two values separately for further use.
Actual:
When I log to console the values stored in array then I get an error saying:
Expected list-like value, got string

Answer 1

The issue is that you are trying to store the return values from the sub keyword as an array/list but returning strings from it.
*** Keywords ***
Main keyword
${OTO_ID} ${LineIdentifier} Run keyword if '${INACTIVEStateCount}'!='0' INACTIVE OTOID selector ${StateCount}
INACTIVE OTOID selector
Return From Keyword If '${OTO_IDStatus}'!='None' ${OTO_ID} ${LineIdentifier}
This will return the values ${OTO_ID} and ${LineIdentifier} as individual variables and not arrays.
Please note that I've ignored the other steps in the sub keyword just to make the answer simpler.
The line(s) that needs to be replaced:
Run Keyword If '${OTO_IDStatus}'!='None' [Return] ${OTO_ID}
Run Keyword If '${OTO_IDStatus}'!='None' [Return] ${LineIdentifier}
Update:
If you want to strictly return the values as list, use below code
*** Keywords ***
Main keyword
${Identifiers} Run keyword if '${INACTIVEStateCount}'!='0' INACTIVE OTOID selector ${StateCount}
INACTIVE OTOID selector
${Identifiers} Create List
.
<Your FOR loop here>
.
\ Run Keyword If '${OTO_IDStatus}'!='None' Append to List ${identifiers} ${OTO_ID} ${LineIdentifier}
Exit For Loop If '${OTO_IDStatus}'!='None'
Return From Keyword If '${OTO_IDStatus}'!='None' ${Identifiers}
Reference : Robot User guide