SYMPTOM:
The following error occurs when accessing or executing a report in Strategy Web 9.x:

Sample Code/Error
Serve Error in '/ Strategy' Application.
A potentially dangerous Request.Form value was detected from the client
(events="...***_4*.***<rsl lcl="1033">***<...").
CAUSE:
One of the possible reasons for this issue is that a unsupported version of the .NET framework is used in IIS.
ACTION:
Use a supported .NET framework version for Strategy Web per readme file