Filter/Hose light comes on

Siemens IQ300 dryer WT36V395GB/14 The dryer continually cuts out after being on for only a couple of minutes. The light stating Filter/Hose comes on. The filter does not appear to be clogged, but we clear it anyway, start the dryer again and within 2 minutes the dryer stops again and the Filter/Hose light comes on again. We restart the dryer and it runs again for a couple of minutes and then stops again. This goes on continuously. It has been doing this for some time. There appears to be nothing wrong with the filter. I have also checked the hose and the external vent and there appears to be nothing wrong with this either.