Okay thanks! I have good news! Another CoP user @Pomi_Daniel faced this issue and shared the solution (The key 'nz0ABmrCGWk' was not found in the namespace 'trackerCaptureGridColumns')
Would you mind trying his solution if it solves the issue? If it doesn’t we’ll try to see what other steps we might need to take! Thank you! (:
BTW, what’s the version of the DHIS2 instance that you are using? (should’ve asked from the start) 
