OS: Windows 10 x64
SlickEdit Pro 2020 (v25.0.1.0 64-bit) with hotfix_se2501_6_cumulative.zip (Revision: 6)
Project files > 10K
Project->Project Properties->refresh, then vs lose response until the whole operation complete.
Depending on the number of the file, it takes some minutes, sometimes above 10 minutes.