We have opened the Salesforce Support case and we received the following response from Salesforce Support Engineer.
- For the first error, this was related to a custom formula field on knowledge which referred another formula field which was dividing one integer rollup-summary field on the sum of itself and another integer rollup-summary field.
Once we deleted or updated the formula to avoid division by zero, this first error has gone.
Strange that this problem doesn't reproduce when we create a Knowledge article record manually through UI or when we insert it by Apex Code.
Salesforce Support Engineer explained that Article Import UI process has unique validations and execution flow which cannot be run outside of Article Import UI process.
- For the second error, this was related to a trigger. When we load 5k records, looks like trigger is executed 25 times and if we have more than 4 SOQL queries in trigger execution, this would cause 101 Too many SOQL queries limit exception.
Deactivation of trigger resolves this issue.
- For the third error, this was related to inline base64-encoded images which didn't end correctly