Fennel This is unlikely to affect your pension. Pension funds spread their investments over a wide range of financial products from cash to bonds to shares and many other and they are constantly making decisions about whether to buy or sell them.
Most of their investments will be in 'blue chip' stocks, that is the shares of large, well-established and financially sound companies that have operated for many years. it will have a market capitalization in the billions, is generally the market leader or among the top three companies in any sector, and is often a household name.
In addition pensions are paid from dividends, rarely from capital release. Not only that but the investment policy and management of pensions is now tightly controlled. There have been problems with pensions being underfunded, but that is a mangement problem, not an investment problem (think BHS)
The problem with the fund you refer to, as I understand it, seems to be that because the fund has fallen in value recently, a lot of investors want to withdraw money, including some very large investors so the fund needs to sell shares to meet these demand. The fund manager wants time to make decisions about what stocks to sell and to sell them so he gets the best value. As I understand it, I do not think the fund is going to go bust.
Of course things can go wrong and who knows what the future will bring, but the problems with this fund are highly unlikely to put anyone's pension in danger.