When saving invoice, no errors and spinning wheel

I just set up my first installation.
Now, I am busy with testing. (I will test small/ big / … invoices …)

But when I will saving my invoice, I get only the spinning wheel.
I don’t get any errors.

My log: https://paste.ee/r/97LE6

I have the exact same problem when i test an invoice with a lot of products. Smaller invoice works ok. After refreshing the invoice list, the large invoice is created so not sure why there is a spinning wheel. The thing we have in common is the Dutch language