Hello,

There is a known issue with the version of Windows 10. You will need to run the fix for the version of windows download the latest windows updates.

Operating System:
Microsoft Windows 10

Minimum Patch Required:
ALM 12.50 Patch 01;(Here answers your question. Now you are using 12.55 patch 2, so it supports.)

Windows 10 Build 1507 (32 Bit):
Microsoft Fix 4048956:
http://support.microsoft.com/kb/KB4048956

Windows 10 32 0R 64-bit Creators Update:
Microsoft Fix 4022716:
http://support.microsoft.com/kb/k4022716.

MicroFocus ALM System Requirements Page
http://admhelp.microfocus.com/alm/specs/alm-qc-system-requirements.htm

Windows 10 supports following browsers to launch HPE ALM/HPE Quality Center Enterprise client.
Microsoft Internet Explorer 10 32 Bit
Microsoft Internet Explorer 11 32 Bit

For customers who have restrictions on plugins in their browsers, such as ActiveX, HPE ALM/QC can be loaded into the HPE ALM Explorer Add-In.
You may also try the ALM Explorer as an alternative in the interim and can find that software through the tools menu or at the following download link for version(12.55) of ALM explorer addin. I am also attaching HPE ALM Explorer Add-In to the case.
https://marketplace.microfocus.com/appdelivery/content/alm-explorer-add