seems like 127 is a programming issue. On large threads with more than 127 pages, it seems to have hit the maximum. 127 is the maximum of a so-called 'signed' 8 bit value (range from -127 to +127, including -0 and +0 makes a total of 256 distinct numbers, thus 8 bit). In this case, the developer of the forum software thought that 8 bits would be enough as threads would not likely go past 100 pages.
The problem here is that none of us wrote the forum software, and this problem runs through the core of the software. Finding a solution to this is not just finding a needle in a haystack, but finding all needles in the haystack, not knowing how many needles there are.