Trying to update a content pack and received this error.

I found a workaround try this. I had 5 reports in my contente pack, so I removed 4 reports and updated my content pack with just one report and no error. I went back and added\updated one report at a time till I added all 5 I oringinally had in the content pack. 

I opened a support ticket ticket with microsoft and they said that it is a known issue and they are working on it. Till then try this workaround.