The cause of German hyperinflation was largely the effect of an artificial constraint on the economy. The German economy was fundamentally strong. It had come out of WWI with its industry almost entirely intact, and with a large well educated populous. It had most of what a 20th century economy needed.

The one thing it was lacking was capital. Between the war loans and the reparations, the government had absolutely no ready cash and their lines of credit were tapped out. So they indulged in the easiest fix, they inflated the currency to get their hands on foreign hard currencies at favorable rates. They had already left the gold standard during the war, making the Mark a fiat currency. This let them make the early reparation payments but put additional inflationary pressure on the Mark. Early responses both within the government and foreign governments exacerbated the problem. France and Belgium invaded the Ruhr to take reparations in raw resource resulting in the coal miners going on strike. Rather than getting payment France just depressed German cash flow further.

In the end the solution was simple (in retrospect). Reparation were eased under the Dawes Plan, a new currency was established, backed by real estate; Germany didn't have enough gold to go back onto a gold standard. And American banks began to re-issue loans to the German government (encouraged by the US government).

With the artificial constraints on the economy eased, Germany's economy started booming again... until the global economy collapsed in 1929. But by then Germany was in a much better situation. She certainly suffered during the Great Depression. But she never went back to wheelbarrows of cash like in 1923.