In every type of investing, there are times where the investment plan does not work out the way it was intended. This is true for freehold property investing, as well as for shares, stocks, bonds, and other financial instruments.
Co-investments are no different: there can be interruptions to income distributions caused by tenant defaults, rental holidays or maintenance issues. There is always the potential for a capital loss, which will affect the value of the capital originally invested. None of these issues are pleasant! Prudent investment at the beginning, though, can usually avoid exposure to many potential problems.
Of course, the greatest protection is the diversification of an investment portfolio with different types of properties.