Trending issue: after installing September 2020 CU and PU custom pages and controls fail to render
After reading this blog post, please also have a look at the following article which includes a recent improvement for PageParserPath September 2020 included a several important security fixes for all supported versions of Sharepoint (2010, 2013, 2016 and 2019). Some of these security fixes have tightend the security requirements for 1st party and 3rd […]