Yes I have tried entering the HST number using the forms mode. The program will not let me change that form unless I override the HST number that is already there.  I have tried overriding the number but when I try to NETFILE I still get this alert: 

Canada Revenue Agency has released new information for the Ontario Staycation tax credit that is not included into this release. If you are claiming this credit, we do not recommend you to Netfile at this time. The Ontario Staycation tax credit changes will be included into our next release. 

Please tell all the people of Ontario, who are claiming this credit, when you are going to upload the release that will let us file our returns. Thanks JP 

A fix for the Staycation credit should be available by the end of this week.

I am having the same problem, it wont let me enter GST number, says that I need to round up to the nearest dollar, I have tried it using the quick step and the form route with no success.

I would also like to know how to enter more than 7 receipts, the number of available slots? 

I am having the same problem, it wont let me enter GST number, says that I need to round up to the nearest dollar, I have tried it using the quick step and the form route with no success.
I would also like to know how to enter more than 7 receipts, the number of available slots?

@ctb75 You can enter the number without the RT, or fill out the ON479 worksheet in Forms mode.

Yeh, did as you instructed using the forms rather than Easy Step and got the same error, didn't matter.

@terryd040959 If you are still not able to resolve this issue, please contact our phone support team at 1-888-829-8608.

People use EasyStep because they find the forms intimidating.  Please fix this problem. You could at the very least open a splash screen directing users to open Forms mode and give a full explanation of how to enter the data.

I left the letters "RT" out of the GST number and my return was successfully netfiled. We will see if this passes CRA muster.

I also left out the RT, all returns efiled and refunds processed without any issues.