There is an opinion on the Internet that these errors are a trouble in MSVC 2019. However I not found how to solve this problem except advice to install another version of MASM.
winextra.inc from include:
; ...
STD_ALERT struct
alrt_timestamp dd ?
alrt_eventname WCHAR [EVLEN + 1] dup(?) ; Here is A2026
alrt_servicename WCHAR [SNLEN + 1] dup(?) ; Here is A2026
STD_ALERT ends
; ...
So how to solve errors A2026 in winextra without reinstallation MASM to another version?
Older versions of MASM accepted the syntax. The newer versions require replacing the square brackets with parentheses.
; ...
STD_ALERT struct
alrt_timestamp dd ?
alrt_eventname WCHAR (EVLEN + 1) dup(?) ; Corrected
alrt_servicename WCHAR (SNLEN + 1) dup(?) ; Corrected
STD_ALERT ends
; ...