I have this problem happen all the time with my InfoPath forms and form libraries. I log into my SP Online account in IE. I go to the form library / Settings / Advanced settings and click Edit Template. I make modifications to the template, save it to my computer, and then try to either Publish or Quick Publish. I get this error most of the time. Does anyone know what causes this? I'm still logged into my account. I added my tenant as a trusted site. Does anyone know how to fix this? Thanks
Do as the below:
Uncheck the “Enable Protected Mode” in IE. Go to IE->Internet Options->Security tab-> Select “Internet” Zone.
When you login to SharePoint Online, check “Keep me signed in”.
I realize this an old post, but if you are like me, and the above fix - as well as the countless others has not worked for you. I thought I should share how I managed to resolve the error:
Rather than saving the form to my hard drive, and then publishing it. I saved it to a location on SharePoint, and published it from there.
It's worth a shot if none of the other suggested fixes has ever worked for you.