Header character corrupt

My designer file have the header.

I try many time, the header name will corrupt, it display a unmeaning string. e.g. Yv1SKIqulr, my original header name should be Recipt Num.

The corrupt header is random, some time this header corrupt and some time other header corrupt.

What's the problem
Thanks

This is a license warning. Please check

for reference.

For a licensed version, these garbage text will not show.

Oh~ IC, Thanks your reply.