There are two most common scenarios — both described below.
1. Cannot overwrite or delete a file
During installation, a red error message appears with the options Retry / Abort / Ignore.
Cause:
The file is in use by another process (e.g., Flexi is running or antivirus software is active).
Solution:
Abort the installation
Restart your computer
Run the installation again
2. Installation "freezes" while copying files
For example, at the stage:
C:\Program Files (x86)\Common Files\WinStrom
Cause:
Antivirus software or the system is blocking access to .exe files.
Solution:
Wait it out (this can take up to ~15 minutes)
If the installation does not resume:
check your antivirus settings
run the installation again
Recommendations
run the installation as an administrator
close Flexi before starting the installation
if issues persist, temporarily disable your antivirus