unable to import dataset on MySQL

In case study 2, I'm unable to import the events table. I followed the steps you mentioned in someone else's doubt but still it's not getting loaded. Its' taking a lot of time to upload but finally it's getting hanged. I'm also unable to import the users table when I specify the activatedat column as datetime datatype, but when I use text datatype it's getting loaded. I think its because there are missing values in activatedat column and I tried specifying the column as default null but still it wont work. The first row of the table is getting inserted because it has all the values, but the 2nd row is missing a value in the activated_at column so that line is showing error. should I continue the analysis by keeping the column as text datatype or is there a way to have null values in a column defined with datetime datatype.