Failed to publish web layer

[TomLek1]

Hi. While attempting to share a web layer from ArcGIS Pro to ArcGIS Online, I keep encountering the following message 'Failed to publish web layer', despite having completed the following steps

1. Added data to map (.csv file that includes latitude and longitude fields)

2. Selected Display XY Data (spatial reference : GCS_WGS_1984)

3. Created feature layer

4. Right clicked on feature layer to 'Share as Web Layer' (Layer Type : Feature)

5. Clicked Analyze (No errors or warnings found)

6. Clicked Publish (error message: 'Failed to publish web layer')

Wonder if anyone has encountered this situation.  Look forward to your advice.

[HCCGISICT_]

Also still having this issue in July 2019. It appears as though I may have added a field to the original data which Adrian Welsh pointed out may be the reason for the overwrite failing.

Is that really the case? How else does one update the data (including a field addition if an overwrite will always fail).

Service definition name remained the same.

Publishing as a new web layer worked but I now have to change the layer in my webmap to the new layer and reconfigure the popups etc. Surely by now the overwrite feature should work or at least provide a better error message rather than "ErrorMessage: Failed to publish web layer". That's about as useful as "Unknown error"