Answer:
First, it is necessary to ensure that the current RFEM/RSTAB version and the Revit version are on the same level. In the best case, you have installed the latest version of each.
If the plugin in Revit is still missing, you can install it as follows:
1. Go to the following folder, according to the system:
- 32-bit system: "C:\Program Files\Common Files\Dlubal\DLInstaller"
- 64-bit system: "C:\Program Files (x86)\Common Files\Dlubal\DLInstaller"
2. Open the DLInstaller.exe program.
3. Go to the "Diagnostics" tab and click "Start".
4. If this does not solve the problem, please send us the report that is generated via "Show Log".
