You can find the supported technologies in the Product Availability Matrix at https://admhelp.microfocus.com/leanft/en/14.50/LeanFT_PAM.pdf
According to that, ALM 11.52 is not supported. I also checked older PAMs back go LeanFT 12.50. ALM 11.52 with patch 7 *is listed* as supported with LeanFT 12.51 and 12.52, **HOWEVER** the PAMs for LeanFT 12.53 and 12.54 show it is **NOT** supported for any version, so there is conflicting information in HPE/Micro Focus documentation.
The best thing to do would be to upgrade your ALM to at least 12.01 Patch 3 and your Lean FT to at least 12.54. The recommended versions are ALM 12.60 and Lean FT 14.50.