Cause:
A variable-type keyword is missing from the srd variable file in the controller's ftp.
Troubleshooting:
Check the error source in the error information area. Use it to find the variable file containing the variable reporting the error, then check whether the variable is defined correctly in that file.
Solution:
Contact after-sales support and modify the srd file reporting the error; complete or delete variables with missing keywords.
Case sharing:
None.