When it comes to finding a replacement for "solution voids," there are a few options available. One possibility is "gaps in solutions," which refers to the absence of an effective solution to a problem. Another alternative is "unresolved issues," which highlights the problems that still need to be solved. "Incomplete solutions" is also a good synonym since it emphasizes that there are still gaps in the existing solutions. Additionally, "problem areas" can be used to describe the parts of an issue that have not yet been addressed or solved. Ultimately, these synonyms all serve to highlight the areas where solutions are lacking and where further work is needed to achieve meaningful progress.