I received the same error, and I didn't even have beam elements in my model. For those of you experiencing this issue, best to create a new study as your currently study may be corrupt.
If you have a complex model, you can drag and drop the parts/connections/constraints from your existing study to the 'new' study.
Hope this helps.
Here are a few suggestions on how to troubleshoot this:
1. Try to isolate and identify a beam body that is the source of the issue by systematically excluding bodies from your study (right-click on a beam body > 'Exclude from Analysis').
2. Check the neutral axis of the beams in your study (right-click on 'Joint group' > 'Edit' and enable the 'Display neutral axis' option).
3. For any beams (especially ones that show a warning about being too short) that appear to have an incorrect neutral axis, right-click on the beam in the Simulation Study Tree > 'Define Beam Neutral Axis'.
4. If the issue persists, it could be due to problematic geometry. Create a new study with only a single body that demonstrates the issue, then try modifying the geometry to simplify until you find that the issue goes away. This may give you a clue as to what is causing the message.
5. If you are using SOLIDWORKS 2014 SP2 or older, this could be related to a known issue (SPR 744781 - "'Internal error. Improper orientation for beam element 32878' error when solving study. Caused by filleted solid treated as beam."). Try upgrading to 2014 SP5 to see if that resolves the issue and contact your SOLIDWORKS Reseller if you need additional assistance.